PHP arrays and collections made easy

Easy and elegant handling of PHP arrays by using an array-like collection object as offered by jQuery and Laravel Collections.

composer req aimeos/map

Supported PHP versions:

• PHP 7.1+
• PHP 8+

Table of contents

• Why PHP Map
• List of methods
  • Create
  • Access
  • Add
  • Aggregate
  • Debug
  • Order
  • Shorten
  • Test
  • Mutate
  • Misc
• Documentation
• Custom methods
• Performance
• Upgrade guide

Why PHP Map

Instead of:

$list = [['id' => 'one', 'value' => 'value1'], ['id' => 'two', 'value' => 'value2'], null];
$list[] = ['id' => 'three', 'value' => 'value3'];    // add element
unset( $list[0] );                                   // remove element
$list = array_filter( $list );                       // remove empty values
sort( $list );                                       // sort elements
$pairs = array_column( $list, 'value', 'id' );       // create ['three' => 'value3']
$value = reset( $pairs ) ?: null;                    // return first value

Only use:

$list = [['id' => 'one', 'value' => 'value1'], ['id' => 'two', 'value' => 'value2'], null];
$value = map( $list )                                // create Map
    ->push( ['id' => 'three', 'value' => 'value3'] ) // add element
    ->remove( 0 )                                    // remove element
    ->filter()                                       // remove empty values
    ->sort()                                         // sort elements
    ->col( 'value', 'id' )                           // create ['three' => 'value3']
    ->first();                                       // return first value

You can still use:

$map[] = ['id' => 'three', 'value' => 'value3'];
$value = $map[0];
count( $map );
foreach( $map as $key => value );

Use callbacks:

Also, the map object allows you to pass anonymous functions to a lot of methods, e.g.:

$map->each( function( $val, $key ) {
	echo $key . ': ' . $val;
} );

jQuery style:

If your map elements are objects, you can call their methods for each object and get the result as new map just like in jQuery:

// MyClass implements setStatus() (returning $this) and getCode() (initialized by constructor)

$map = Map::from( ['a' => new MyClass( 'x' ), 'b' => new MyClass( 'y' )] );
$map->setStatus( 1 )->getCode()->toArray();

This will call setStatus( 1 ) on both objects. If setStatus() implementation returns $this, the new map will also contain:

['a' => MyClass(), 'b' => MyClass()]

On those new map elements, getCode() will be called which returns x for the first object and y for the second. The map created from the results of getCode() will return:

['a' => 'x', 'b' => 'y']

Methods

Create

• function map() : Creates a new map from passed elements
• __construct() : Creates a new map
• clone() : Clones the map and all objects within
• copy() : Creates a new copy
• explode() : Splits a string into a map of elements
• from() : Creates a new map from passed elements
• fromJson() : Creates a new map from a JSON string
• times() : Creates a new map by invoking the closure a number of times
• tree() : Creates a tree structure from the list items

Access

• __call() : Calls a custom method
• __callStatic() : Calls a custom method statically
• all() : Returns the plain array
• at() : Returns the value at the given position
• bool() : Returns an element by key and casts it to boolean
• call() : Calls the given method on all items
• find() : Returns the first/last matching element
• first() : Returns the first element
• firstKey() : Returns the first key
• get() : Returns an element by key
• index() : Returns the numerical index of the given key
• int() : Returns an element by key and casts it to integer
• float() : Returns an element by key and casts it to float
• keys() : Returns all keys
• last() : Returns the last element
• lastKey() : Returns the last key
• pop() : Returns and removes the last element
• pos() : Returns the numerical index of the value
• pull() : Returns and removes an element by key
• random() : Returns random elements preserving keys
• search() : Find the key of an element
• shift() : Returns and removes the first element
• string() : Returns an element by key and casts it to string
• toArray() : Returns the plain array
• unique() : Returns all unique elements preserving keys
• values() : Returns all elements with new keys

Add

• concat() : Adds all elements with new keys
• insertAfter() : Inserts the value after the given element
• insertAt() : Inserts the element at the given position in the map
• insertBefore() : Inserts the value before the given element
• merge() : Combines elements overwriting existing ones
• pad() : Fill up to the specified length with the given value
• prepend() : Adds an element at the beginning (alias)
• push() : Adds an element to the end
• put() : Sets the given key and value in the map (alias)
• set() : Overwrites or adds an element
• union() : Adds the elements without overwriting existing ones
• unshift() : Adds an element at the beginning
• with() : Returns a copy and sets an element

Aggregate

• avg() : Returns the average of all values
• count() : Returns the total number of elements
• countBy() : Counts how often the same values are in the map
• max() : Returns the maximum value of all elements
• min() : Returns the minium value of all elements
• percentage() : Returns the percentage of all elements passing the test
• sum() : Returns the sum of all values in the map

Debug

• dd() : Prints the map content and terminates the script
• dump() : Prints the map content
• tap() : Passes a clone of the map to the given callback

Order By

• arsort() : Reverse sort elements preserving keys
• asort() : Sort elements preserving keys
• krsort() : Reverse sort elements by keys
• ksort() : Sort elements by keys
• order() : Orders elements by the passed keys
• reverse() : Reverses the array order preserving keys
• reversed() : Reverses the element order in a copy of the map
• toReversed() : Reverses the element order in a copy of the map (alias)
• rsort() : Reverse sort elements using new keys
• shuffle() : Randomizes the element order
• shuffled() : Randomizes the element order in a copy of the map
• sort() : Sorts the elements in-place assigning new keys
• sorted() : Sorts the elements in a copy of the map using new keys
• toSorted() : Sorts the elements in a copy of the map using new keys (alias)
• uasort() : Sorts elements preserving keys using callback
• uksort() : Sorts elements by keys using callback
• usort() : Sorts elements using callback assigning new keys

Shorten

• after() : Returns the elements after the given one
• before() : Returns the elements before the given one
• clear() : Removes all elements
• diff() : Returns the elements missing in the given list
• diffAssoc() : Returns the elements missing in the given list and checks keys
• diffKeys() : Returns the elements missing in the given list by keys
• except() : Returns a new map without the passed element keys
• filter() : Applies a filter to all elements
• grep() : Applies a regular expression to all elements
• intersect() : Returns the elements shared
• intersectAssoc() : Returns the elements shared and checks keys
• intersectKeys() : Returns the elements shared by keys
• nth() : Returns every nth element from the map
• only() : Returns only those elements specified by the keys
• pop() : Returns and removes the last element
• pull() : Returns and removes an element by key
• reject() : Removes all matched elements
• remove() : Removes an element by key
• shift() : Returns and removes the first element
• skip() : Skips the given number of items and return the rest
• slice() : Returns a slice of the map
• take() : Returns a new map with the given number of items
• where() : Filters the list of elements by a given condition

Test

• function is_map() : Tests if the variable is a map object
• compare() : Compares the value against all map elements
• contains() : Tests if an item exists in the map
• each() : Applies a callback to each element
• empty() : Tests if map is empty
• equals() : Tests if map contents are equal
• every() : Verifies that all elements pass the test of the given callback
• has() : Tests if a key exists
• if() : Executes callbacks depending on the condition
• ifAny() : Executes callbacks if the map contains elements
• ifEmpty() : Executes callbacks if the map is empty
• in() : Tests if element is included
• includes() : Tests if element is included
• inString() : Tests if the item is part of the strings in the map
• is() : Tests if the map consists of the same keys and values
• isEmpty() : Tests if map is empty
• isNumeric() : Tests if all entries are numeric values
• isObject() : Tests if all entries are objects
• isScalar() : Tests if all entries are scalar values.
• isString() : Tests if all entries are string values.
• implements() : Tests if all entries are objects implementing the interface
• none() : Tests if none of the elements are part of the map
• some() : Tests if at least one element is included
• strContains() : Tests if at least one of the passed strings is part of at least one entry
• strContainsAll() : Tests if all of the entries contains one of the passed strings
• strEnds() : Tests if at least one of the entries ends with one of the passed strings
• strEndsAll() : Tests if all of the entries ends with at least one of the passed strings
• strStarts() : Tests if at least one of the entries starts with at least one of the passed strings
• strStartsAll() : Tests if all of the entries starts with one of the passed strings

Mutate

• cast() : Casts all entries to the passed type
• chunk() : Splits the map into chunks
• col() : Creates a key/value mapping
• collapse() : Collapses multi-dimensional elements overwriting elements
• combine() : Combines the map elements as keys with the given values
• flat() : Flattens multi-dimensional elements without overwriting elements
• flip() : Exchanges keys with their values
• groupBy() : Groups associative array elements or objects
• join() : Returns concatenated elements as string with separator
• ltrim() : Removes the passed characters from the left of all strings
• map() : Applies a callback to each element and returns the results
• partition() : Breaks the list into the given number of groups
• pipe() : Applies a callback to the whole map
• pluck() : Creates a key/value mapping (alias)
• prefix() : Adds a prefix to each map entry
• reduce() : Computes a single value from the map content
• rekey() : Changes the keys according to the passed function
• replace() : Replaces elements recursively
• rtrim() : Removes the passed characters from the right of all strings
• splice() : Replaces a slice by new elements
• strAfter() : Returns the strings after the passed value
• strLower() : Converts all alphabetic characters to lower case
• strReplace() : Replaces all occurrences of the search string with the replacement string
• strUpper() : Converts all alphabetic characters to upper case
• suffix() : Adds a suffix to each map entry
• toJson() : Returns the elements in JSON format
• toUrl() : Creates a HTTP query string
• transfrom() : Applies a callback to each element which creates new key/value pairs
• transpose() : Exchanges rows and columns for a two dimensional map
• traverse() : Traverses trees of nested items passing each item to the callback
• trim() : Removes the passed characters from the left/right of all strings
• walk() : Applies the given callback to all elements
• zip() : Merges the values of all arrays at the corresponding index

Misc

• delimiter() : Sets or returns the seperator for paths to multi-dimensional arrays
• getIterator() : Returns an iterator for the elements
• jsonSerialize() : Specifies the data which should be serialized to JSON
• method() : Registers a custom method
• offsetExists() : Checks if the key exists
• offsetGet() : Returns an element by key
• offsetSet() : Overwrites an element
• offsetUnset() : Removes an element by key
• sep() : Sets the seperator for paths to multi-dimensional arrays in the current map

Method documentation

is_map() function

Tests if the variable is a map object

function is_map( $var ) : bool

• @param mixed $var Variable to test

Examples:

is_map( new Map() );
// true

is_map( [] );
// false

map() function

Returns a new map for the passed elements.

function map( $elements = [] ) : \Aimeos\Map

• @param mixed $elements List of elements or single value
• @return \Aimeos\Map Map instance

Examples:

// array
map( [] );

// null
map( null );

// scalar
map( 'a' );

// object
map( new \stdClass() );

// map object
map( new Map() );

// iterable object
map( new ArrayObject() );

// closure evaluated lazily
map( function() {
    return [];
} );

See also:

• rekey() - Changes the keys according to the passed function
• transform() - Creates new key/value pairs using the passed function and returns a new map for the result

__construct()

Creates a new map object.

public function __construct( $elements = [] )

• @param mixed $elements Single element, list of elements, Map object, iterable objects or iterators, everything else

Examples:

// array
new Map( [] );

// null
new Map( null );

// scalar
new Map( 'a' );

// object
new Map( new \stdClass() );

// map object
new Map( new Map() );

// iterable object
new Map( new ArrayObject() );

// closure evaluated lazily
new Map( function() {
    return [];
} );

__call()

Handles dynamic calls to custom methods for the class.

public function __call( string $name, array $params )

• @param string $name Method name
• @param array<mixed> $params List of parameters
• @return mixed Result from called function or new map with results from the element methods

Calls a custom method added by Map::method(). The called method has access to the internal array by using $this->items.

Examples:

Map::method( 'case', function( $case = CASE_LOWER ) {
    return new self( array_change_key_case( $this->items, $case ) );
} );

Map::from( ['a' => 'bar'] )->case( CASE_UPPER );
// ['A' => 'bar']

This does also allow calling object methods if the items are objects:

$item = new MyClass(); // with method setStatus() (returning $this) and getCode() implemented
Map::from( [$item, $item] )->setStatus( 1 )->getCode()->toArray();

This will call the setStatus() method of each element in the map and use their return values to create a new map. On the new map, the getCode() method is called for every element and its return values are also stored in a new map. This last map is then returned and the map keys from the original map are preserved in the returned map.

If the elements are not objects, they are skipped and if this applies to all elements, an empty map is returned. In case the map contains objects of mixed types and one of them doesn’t implement the called method, an error will be thrown.

__callStatic()

Handles static calls to custom methods for the class.

public static function __callStatic( string $name, array $params )

• @param string $name Method name
• @param array<mixed> $params List of parameters
• @return mixed Result from called function or new map with results from the element methods
• @throws \BadMethodCallException If no method has been registered for that name

Calls a custom method added by Map::method() statically. The called method has no access to the internal array because no object is available.

Examples:

Map::method( 'foo', function( $arg1, $arg2 ) {} );
Map::foo( $arg1, $arg2 );

after()

Returns the elements after the given one.

public function after( $value ) : self

• @param \Closure|int|string $value Value or function with (item, key) parameters
• @return self<int|string,mixed> New map with the elements after the given one

The keys are preserved using this method.

Examples:

Map::from( [0 => 'b', 1 => 'a'] )->after( 'b' );
// [1 => 'a']

Map::from( ['a' => 1, 'b' => 0] )->after( 1 );
// ['b' => 0]

Map::from( [0 => 'b', 1 => 'a'] )->after( 'c' );
// []

Map::from( ['a', 'c', 'b'] )->after( function( $item, $key ) {
    return $item >= 'c';
} );
// [2 => 'b']

all()

Returns the elements as a plain array.

public function all() : array

• @return array Plain array

Examples:

Map::from( ['a'] )->all();
// ['a']

arsort()

Sorts all elements in reverse order and maintains the key association.

public function arsort( int $options = SORT_REGULAR ) : self

• @param int $options Sort options for arsort()
• @return self<int|string,mixed> Updated map for fluid interface

The keys are preserved using this method and no new map is created.

The $options parameter modifies how the values are compared. Possible parameter values are:

• SORT_REGULAR : compare elements normally (don’t change types)
• SORT_NUMERIC : compare elements numerically
• SORT_STRING : compare elements as strings
• SORT_LOCALE_STRING : compare elements as strings, based on the current locale or changed by setlocale()
• SORT_NATURAL : compare elements as strings using “natural ordering” like natsort()
• SORT_FLAG_CASE : use SORT_STRING|SORT_FLAG_CASE and SORT_NATURAL|SORT_FLAG_CASE to sort strings case-insensitively

Examples:

Map::from( ['b' => 0, 'a' => 1] )->arsort();
// ['a' => 1, 'b' => 0]

Map::from( ['a', 'b'] )->arsort();
// ['b', 'a']

Map::from( [0 => 'C', 1 => 'b'] )->arsort();
// [1 => 'b', 0 => 'C']

Map::from( [0 => 'C', 1 => 'b'] )->arsort( SORT_STRING|SORT_FLAG_CASE );
// [0 => 'C', 1 => 'b'] because 'C' -> 'c' and 'c' > 'b'

asort()

Sorts all elements and maintains the key association.

public function asort( int $options = SORT_REGULAR ) : self

• @param int $options Sort options for asort()
• @return self<int|string,mixed> Updated map for fluid interface

The keys are preserved using this method and no new map is created.

The parameter modifies how the values are compared. Possible parameter values are:

• SORT_REGULAR : compare elements normally (don’t change types)
• SORT_NUMERIC : compare elements numerically
• SORT_STRING : compare elements as strings
• SORT_LOCALE_STRING : compare elements as strings, based on the current locale or changed by setlocale()
• SORT_NATURAL : compare elements as strings using “natural ordering” like natsort()
• SORT_FLAG_CASE : use SORT_STRING|SORT_FLAG_CASE and SORT_NATURAL|SORT_FLAG_CASE to sort strings case-insensitively

Examples:

Map::from( ['a' => 1, 'b' => 0] )->asort();
// ['b' => 0, 'a' => 1]

Map::from( [0 => 'b', 1 => 'a'] )->asort();
// [1 => 'a', 0 => 'b']

Map::from( [0 => 'C', 1 => 'b'] )->asort();
// [0 => 'C', 1 => 'b'] because 'C' < 'b'

Map::from( [0 => 'C', 1 => 'b'] )->arsort( SORT_STRING|SORT_FLAG_CASE );
// [1 => 'b', 0 => 'C'] because 'C' -> 'c' and 'c' > 'b'

at()

Returns the value at the given position.

public function at( int $pos )

• @param int $pos Position of the value in the map
• @return mixed†null Value at the given position or NULL if no value is available

The position starts from zero and a position of “0” returns the first element of the map, “1” the second and so on. If the position is negative, the sequence will start from the end of the map.

Examples:

Map::from( [1, 3, 5] )->at( 0 );
// 1

Map::from( [1, 3, 5] )->at( 1 );
// 3

Map::from( [1, 3, 5] )->at( -1 );
// 5

Map::from( [1, 3, 5] )->at( 3 );
// NULL

avg()

Returns the average of all integer and float values in the map.

public function avg( $col = null ) : float

• @param Closure|string|null $col Closure, key or path to the values in the nested array or object to compute the average for
• @return float Average of all elements or 0 if there are no elements in the map

NULL values are treated as 0, non-numeric values will generate an error.

This does also work for multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. “key1/key2/key3” to get “val” from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( [1, 3, 5] )->avg();
// 3

Map::from( [1, null, 5] )->avg();
// 3

Map::from( [1, 'sum', 5] )->avg();
// 2

Map::from( [['p' => 30], ['p' => 50], ['p' => 10]] )->avg( 'p' );
// 30

Map::from( [['i' => ['p' => 30]], ['i' => ['p' => 50]]] )->avg( 'i/p' );
// 40

Map::from( [30, 50, 10] )->avg( fn( $val, $key ) => $val < 50 );
// 20

before()

Returns the elements before the given one.

public function before( $value ) : self

• @param \Closure|int|string $value Value or function with (item, key) parameters
• @return self<int|string,mixed> New map with the elements before the given one

The keys are preserved using this method.

Examples:

Map::from( ['a' => 1, 'b' => 0] )->before( 0 );
// ['a' => 1]

Map::from( [0 => 'b', 1 => 'a'] )->before( 'a' );
// [0 => 'b']

Map::from( [0 => 'b', 1 => 'a'] )->before( 'c' );
// []

Map::from( ['a', 'c', 'b'] )->before( function( $item, $key ) {
    return $key >= 1;
} );
// [0 => 'a']

bool()

Returns an element by key and casts it to boolean if possible.

public function bool( $key, $default = false ) : bool

• @param int|string $key Key or path to the requested item
• @param mixed $default Default value if key isn’t found (will be casted to bool)
• @return bool Value from map or default value

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( ['a' => true] )->bool( 'a' );
// true

Map::from( ['a' => '1'] )->bool( 'a' );
// true (casted to boolean)

Map::from( ['a' => 1.1] )->bool( 'a' );
// true (casted to boolean)

Map::from( ['a' => '10'] )->bool( 'a' );
// true (casted to boolean)

Map::from( ['a' => 'abc'] )->bool( 'a' );
// true (casted to boolean)

Map::from( ['a' => ['b' => ['c' => true]]] )->bool( 'a/b/c' );
// true

Map::from( [] )->bool( 'c', function() { return rand( 1, 2 ); } );
// true (value returned by closure is casted to boolean)

Map::from( [] )->bool( 'a', true );
// true (default value used)

Map::from( [] )->bool( 'a' );
// false

Map::from( ['b' => ''] )->bool( 'b' );
// false (casted to boolean)

Map::from( ['b' => null] )->bool( 'b' );
// false (null is not scalar)

Map::from( ['b' => [true]] )->bool( 'b' );
// false (arrays are not scalar)

Map::from( ['b' => '#resource'] )->bool( 'b' );
// false (resources are not scalar)

Map::from( ['b' => new \stdClass] )->bool( 'b' );
// false (objects are not scalar)

Map::from( [] )->bool( 'c', new \Exception( 'error' ) );
// throws exception

call()

Calls the given method on all items and returns the result.

public function call( string $name, array $params = [] ) : self

• @param string $name Method name
• @param array<mixed> $params List of parameters
• @return self<int|string,mixed> New map with results from all elements

This method can call methods on the map entries that are also implemented by the map object itself and are therefore not reachable when using the magic __call() method. If some entries are not objects, they will be skipped.

The keys from the original map are preserved in the returned in the new map.

Examples:

$item = new MyClass( ['myprop' => 'val'] ); // implements methods get() and toArray()

Map::from( [$item, $item] )->call( 'get', ['myprop'] );
// ['val', 'val']

Map::from( [$item, $item] )->call( 'toArray' );
// [['myprop' => 'val'], ['myprop' => 'val']]

cast()

Casts all entries to the passed type.

public function cast( string $type = 'string' ) : self

• @param string $type Type to cast the values to (“string”, “bool”, “int”, “float”, “array”, “object”)
• @return self<int|string,mixed> Updated map with casted elements

Casting arrays and objects to scalar values won’t return anything useful!

Examples:

Map::from( [true, 1, 1.0, 'yes'] )->cast();
// ['1', '1', '1.0', 'yes']

Map::from( [true, 1, 1.0, 'yes'] )->cast( 'bool' );
// [true, true, true, true]

Map::from( [true, 1, 1.0, 'yes'] )->cast( 'int' );
// [1, 1, 1, 0]

Map::from( [true, 1, 1.0, 'yes'] )->cast( 'float' );
// [1.0, 1.0, 1.0, 0.0]

Map::from( [new stdClass, new stdClass] )->cast( 'array' );
// [[], []]

Map::from( [[], []] )->cast( 'object' );
// [new stdClass, new stdClass]

chunk()

Chunks the map into arrays with the given number of elements.

public function chunk( int $size, bool $preserve = false ) : self

• @param int $size Maximum size of the sub-arrays
• @param bool $preserve Preserve keys in new map
• @return self<int|string,mixed> New map with elements chunked in sub-arrays
• @throws \InvalidArgumentException If size is smaller than 1

The last chunk may contain less elements than the given number.

The sub-arrays of the returned map are plain PHP arrays. If you need Map objects, then wrap them with Map::from() when you iterate over the map.

Examples:

Map::from( [0, 1, 2, 3, 4] )->chunk( 3 );
// [[0, 1, 2], [3, 4]]

Map::from( ['a' => 0, 'b' => 1, 'c' => 2] )->chunk( 2 );
// [['a' => 0, 'b' => 1], ['c' => 2]]

clear()

Removes all elements from the current map.

public function clear() : self

• @return self<int|string,mixed> Updated map for fluid interface

Examples:

Map::from( [0, 1] )->clear();
// internal : []

clone()

Clones the map and all objects within.

public function clone() : self

• @return self<int|string,mixed> New map with cloned objects

The objects within the Map are NOT the same as before but new cloned objects. This is different to copy(), which doesn’t clone the objects within.

The keys are preserved using this method.

Examples:

Map::from( [new \stdClass, new \stdClass] )->clone();
// [new \stdClass, new \stdClass]

col()

Returns the values of a single column/property from an array of arrays or list of elements in a new map.

public function col( string $valuecol = null, string $indexcol = null ) : self

• @param string|null $valuecol Name or path of the value property
• @param string|null $indexcol Name or path of the index property
• @return self<int|string,mixed> New map with mapped entries

If $indexcol is omitted, it’s value is NULL or not set, the result will be indexed from 0-n. Items with the same value for $indexcol will overwrite previous items and only the last one will be part of the resulting map.

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( [['id' => 'i1', 'val' => 'v1'], ['id' => 'i2', 'val' => 'v2']] )->col( 'val' );
// ['v1', 'v2']

Map::from( [['id' => 'i1', 'val' => 'v1'], ['id' => 'i2', 'val' => 'v2']] )->col( 'val', 'id' );
// ['i1' => 'v1', 'i2' => 'v2']

Map::from( [['id' => 'i1', 'val' => 'v1'], ['id' => 'i2', 'val' => 'v2']] )->col( null, 'id' );
// ['i1' => ['id' => 'i1', 'val' => 'v1'], 'i2' => ['id' => 'i2', 'val' => 'v2']]

Map::from( [['id' => 'ix', 'val' => 'v1'], ['id' => 'ix', 'val' => 'v2']] )->col( null, 'id' );
// ['ix' => ['id' => 'ix', 'val' => 'v2']]

Map::from( [['foo' => ['bar' => 'one', 'baz' => 'two']]] )->col( 'foo/baz', 'foo/bar' );
// ['one' => 'two']

Map::from( [['foo' => ['bar' => 'one']]] )->col( 'foo/baz', 'foo/bar' );
// ['one' => null]

Map::from( [['foo' => ['baz' => 'two']]] )->col( 'foo/baz', 'foo/bar' );
// ['two']

collapse()

Collapses all sub-array elements recursively to a new map.

public function collapse( int $depth = null ) : self

• @param int|null $depth Number of levels to collapse for multi-dimensional arrays or NULL for all
• @return self<int|string,mixed> New map with all sub-array elements added into it recursively, up to the specified depth

The keys are preserved and already existing elements will be overwritten. This is also true for numeric keys! This method is similar than flat() but replaces already existing elements.

A value smaller than 1 for depth will return the same map elements. Collapsing does also work if elements implement the “Traversable” interface (which the Map object does).

Examples:

Map::from( [0 => ['a' => 0, 'b' => 1], 1 => ['c' => 2, 'd' => 3]] )->collapse();
// ['a' => 0, 'b' => 1, 'c' => 2, 'd' => 3]

Map::from( [0 => ['a' => 0, 'b' => 1], 1 => ['a' => 2]] )->collapse();
// ['a' => 2, 'b' => 1]

Map::from( [0 => [0 => 0, 1 => 1], 1 => [0 => ['a' => 2, 0 => 3], 1 => 4]] )->collapse();
// [0 => 3, 1 => 4, 'a' => 2]

Map::from( [0 => [0 => 0, 'a' => 1], 1 => [0 => ['b' => 2, 0 => 3], 1 => 4]] )->collapse( 1 );
// [0 => ['b' => 2, 0 => 3], 1 => 4, 'a' => 1]

Map::from( [0 => [0 => 0, 'a' => 1], 1 => Map::from( [0 => ['b' => 2, 0 => 3], 1 => 4] )] )->collapse();
// [0 => 3, 'a' => 1, 'b' => 2, 1 => 4]

combine()

Combines the values of the map as keys with the passed elements as values.

public function combine( iterable $values ) : self

• @param iterable<int|string,mixed> $values Values of the new map
• @return self<int|string,mixed> New map

Examples:

Map::from( ['name', 'age'] )->combine( ['Tom', 29] );
// ['name' => 'Tom', 'age' => 29]

compare()

Compares the value against all map elements.

public function compare( string $value, bool $case = true ) : bool

• @param string $value Value to compare map elements to
• @param bool $case TRUE if comparison is case sensitive, FALSE to ignore upper/lower case
• @return bool TRUE If at least one element matches, FALSE if value is not in map

All scalar values (bool, float, int and string) are casted to string values before comparing to the given value. Non-scalar values in the map are ignored.

Examples:

Map::from( ['foo', 'bar'] )->compare( 'foo' );
// true

Map::from( ['foo', 'bar'] )->compare( 'Foo', false );
// true (case insensitive)

Map::from( [123, 12.3] )->compare( '12.3' );
// true

Map::from( [false, true] )->compare( '1' );
// true

Map::from( ['foo', 'bar'] )->compare( 'Foo' );
// false (case sensitive)

Map::from( ['foo', 'bar'] )->compare( 'baz' );
// false

Map::from( [new \stdClass(), 'bar'] )->compare( 'foo' );
// false

concat()

Pushs all of the given elements onto the map without creating a new map.

public function concat( iterable $elements ) : self

• @param iterable<int|string,mixed> $elements List of elements
• @return self<int|string,mixed> Updated map for fluid interface

The keys of the passed elements are NOT preserved!

Examples:

Map::from( ['foo'] )->concat( ['bar'] );
// ['foo', 'bar']

Map::from( ['foo'] )->concat( new Map( ['bar' => 'baz'] ) );
// ['foo', 'baz']

contains()

Determines if an item exists in the map.

public function contains( $key, string $operator = null, $value = null ) : bool

This method combines the power of the where() method with some() to check if the map contains at least one of the passed values or conditions.

• @param \Closure|iterable|mixed $values Anonymous function with (item, key) parameter, element or list of elements to test against
• @param string|null $op Operator used for comparison
• @param mixed $value Value used for comparison
• @return bool TRUE if at least one element is available in map, FALSE if the map contains none of them

Check the where()] method for available operators.

Examples:

Map::from( ['a', 'b'] )->contains( 'a' );
// true

Map::from( ['a', 'b'] )->contains( ['a', 'c'] );
// true

Map::from( ['a', 'b'] )->contains( function( $item, $key ) {
    return $item === 'a'
} );
// true

Map::from( [['type' => 'name']] )->contains( 'type', 'name' );
// true

Map::from( [['type' => 'name']] )->contains( 'type', '!=', 'name' );
// false

copy()

Creates a new map with the same elements.

public function copy() : self

• @return self<int|string,mixed> New map

Both maps share the same array until one of the map objects modifies the array. Then, the array is copied and the copy is modfied (copy on write).

Examples:

$m = Map::from( ['foo', 'bar'] );

$m2 = $m->copy();
// internal: ['foo', 'bar'] both two maps

count()

Counts the number of elements in the map.

public function count() : int

• @return int Number of elements

Examples:

Map::from( ['foo', 'bar'] )->count();
// 2

countBy()

Counts how often the same values are in the map.

public function countBy( callable $callback = null ) : self

• @param callable|null $callback Function with (value, key) parameters which returns the value to use for counting
• @return self<int|string,mixed> New map with values as keys and their count as value

Examples:

Map::from( [1, 'foo', 2, 'foo', 1] )->countBy();
// [1 => 2, 'foo' => 2, 2 => 1]

Map::from( [1.11, 3.33, 3.33, 9.99] )->countBy();
// ['1.11' => 1, '3.33' => 2, '9.99' => 1]

Map::from( ['a@gmail.com', 'b@yahoo.com', 'c@gmail.com'] )->countBy( function( $email ) {
    return substr( strrchr( $email, '@' ), 1 );
} );
// ['gmail.com' => 2, 'yahoo.com' => 1]

dd()

Dumps the map content and terminates the script.

public function dd( callable $callback = null ) : void

• @param callable|null $callback Function receiving the map elements as parameter (optional)

The dd() method is very helpful to see what are the map elements passed between two map methods in a method call chain. It stops execution of the script afterwards to avoid further output.

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->sort()->dd()->first();
/*
Array
(
    [0] => bar
    [1] => foo
)
*/

The first() method isn’t executed at all.

delimiter()

Sets or returns the seperator for paths to values in multi-dimensional arrays or objects.

public static function delimiter( ?string $char = null ) : string

• @param string $char Separator character, e.g. “.” for “key.to.value” instaed of “key/to/value”
• @return string Separator used up to now

The static method only changes the separator for new maps created afterwards. Already existing maps will continue to use the previous separator. To change the separator of an existing map, use the sep() method instead.

Examples:

Map::delimiter( '.' );
// '/'

Map::from( ['foo' => ['bar' => 'baz']] )->get( 'foo.bar' );
// 'baz'

diff()

Returns the keys/values in the map whose values are not present in the passed elements in a new map.

public function diff( iterable $elements, callable $callback = null ) : self

• @param iterable<int|string,mixed> $elements List of elements
• @param callable|null $callback Function with (valueA, valueB) parameters and returns -1 (<), 0 (=) and 1 (>)
• @return self<int|string,mixed> New map

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->diff( ['bar'] );
// ['a' => 'foo']

If a callback is passed, the given function will be used to compare the values. The function must accept two parameters (value A and B) and must return -1 if value A is smaller than value B, 0 if both are equal and 1 if value A is greater than value B. Both, a method name and an anonymous function can be passed:

Map::from( [0 => 'a'] )->diff( [0 => 'A'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diff( ['B' => 'A'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diff( ['c' => 'A'], function( $valA, $valB ) {
    return strtolower( $valA ) <=> strtolower( $valB );
} );
// []

All examples will return an empty map because both contain the same values when compared case insensitive.

The keys are preserved using this method.

diffAssoc()

Returns the keys/values in the map whose keys AND values are not present in the passed elements in a new map.

public function diffAssoc( iterable $elements, callable $callback = null ) : self

• @param iterable<int|string,mixed> $elements List of elements
• @param callable|null $callback Function with (valueA, valueB) parameters and returns -1 (<), 0 (=) and 1 (>)
• @return self<int|string,mixed> New map

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->diffAssoc( new Map( ['foo', 'b' => 'bar'] ) );
// ['a' => 'foo']

If a callback is passed, the given function will be used to compare the values. The function must accept two parameters (valA, valB) and must return -1 if value A is smaller than value B, 0 if both are equal and 1 if value A is greater than value B. Both, a method name and an anonymous function can be passed:

Map::from( [0 => 'a'] )->diffAssoc( [0 => 'A'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diffAssoc( ['B' => 'A'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diffAssoc( ['c' => 'A'], function( $valA, $valB ) {
    return strtolower( $valA ) <=> strtolower( $valB );
} );
// ['b' => 'a']

The first and second example will return an empty map because both contain the same values when compared case insensitive. In the third example, the keys doesn’t match (“b” vs. “c”).

The keys are preserved using this method.

diffKeys()

Returns the key/value pairs from the map whose keys are not present in the passed elements in a new map.

public function diffKeys( iterable $elements, callable $callback = null ) : self

• @param iterable<int|string,mixed> $elements List of elements
• @param callable|null $callback Function with (keyA, keyB) parameters and returns -1 (<), 0 (=) and 1 (>)
• @return self<int|string,mixed> New map

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->diffKeys( new Map( ['foo', 'b' => 'baz'] ) );
// ['a' => 'foo']

If a callback is passed, the given function will be used to compare the keys. The function must accept two parameters (key A and B) and must return -1 if key A is smaller than key B, 0 if both are equal and 1 if key A is greater than key B. Both, a method name and an anonymous function can be passed:

Map::from( [0 => 'a'] )->diffKeys( [0 => 'A'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diffKeys( ['B' => 'X'], 'strcasecmp' );
// []

Map::from( ['b' => 'a'] )->diffKeys( ['c' => 'a'], function( $keyA, $keyB ) {
    return strtolower( $keyA ) <=> strtolower( $keyB );
} );
// ['b' => 'a']

The first and second example will return an empty map because both contain the same keys when compared case insensitive. The third example will return [‘b’ => ‘a’] because the keys doesn’t match (“b” vs. “c”).

The keys are preserved using this method.

dump()

Dumps the map content using the given function (print_r by default).

public function dump( callable $callback = null ) : self

• @param callable|null $callback Function receiving the map elements as parameter (optional)
• @return self<int|string,mixed> Same map for fluid interface

The dump() method is very helpful to see what are the map elements passed between two map methods in a method call chain.

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->dump()->asort()->dump( 'var_dump' );
/*
Array
(
    [a] => foo
    [b] => bar
)

array(1) {
  ["b"]=>
  string(3) "bar"
  ["a"]=>
  string(3) "foo"
}
*/

duplicates()

Returns the duplicate values from the map.

public function duplicates( string $col = null ) : self

• @param string|null $col Key of the nested array or object to check for
• @return self<int|string,mixed> New map

For nested arrays, you have to pass the name of the column of the nested array which should be used to check for duplicates.

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

The keys in the result map are preserved.

Examples:

Map::from( [1, 2, '1', 3] )->duplicates()
// [2 => '1']

Map::from( [['p' => '1'], ['p' => 1], ['p' => 2]] )->duplicates( 'p' )
// [1 => ['p' => 1]]

Map::from( [['i' => ['p' => '1']], ['i' => ['p' => 1]]] )->duplicates( 'i/p' )
// [1 => ['i' => ['p' => '1']]]

each()

Executes a callback over each entry until FALSE is returned.

public function each( \Closure $callback ) : self

• @param \Closure $callback Function with (value, key) parameters and returns TRUE/FALSE
• @return self<int|string,mixed> Same map for fluid interface

Examples:

$result = [];
Map::from( [0 => 'a', 1 => 'b'] )->each( function( $value, $key ) use ( &$result ) {
    $result[$key] = strtoupper( $value );
    return false;
} );
// $result = [0 => 'A']

The $result array will contain [0 => 'A'] because FALSE is returned after the first entry and all other entries are then skipped.

empty()

Determines if the map is empty or not.

public function empty() : bool

• @return bool TRUE if map is empty, FALSE if not

The method is equivalent to isEmpty().

Examples:

Map::from( [] )->empty();
// true

Map::from( ['a'] )->empty();
// false

equals()

Tests if the passed elements are equal to the elements in the map.

public function equals( iterable $elements ) : bool

• @param iterable<int|string,mixed> $elements List of elements to test against
• @return bool TRUE if both are equal, FALSE if not

The method differs to is() in the fact that it doesn’t care about the keys by default. The elements are only loosely compared and the keys are ignored.

Values are compared by their string values:

(string) $item1 === (string) $item2

Examples:

Map::from( ['a'] )->equals( ['a', 'b'] );
// false

Map::from( ['a', 'b'] )->equals( ['b'] );
// false

Map::from( ['a', 'b'] )->equals( ['b', 'a'] );
// true

every()

Verifies that all elements pass the test of the given callback.

public function every( \Closure $callback ) : bool

• @param \Closure $callback Function with (value, key) parameters and returns TRUE/FALSE
• @return bool True if all elements pass the test, false if if fails for at least one element

Examples:

Map::from( [0 => 'a', 1 => 'b'] )->every( function( $value, $key ) {
    return is_string( $value );
} );
// true

Map::from( [0 => 'a', 1 => 100] )->every( function( $value, $key ) {
    return is_string( $value );
} );
// false

except()

Returns a new map without the passed element keys.

public function except( $keys ) : self

• @param iterable<int|string>|array<int|string>|string|int $keys List of keys to remove
• @return self<int|string,mixed> New map

The keys in the result map are preserved.

Examples:

Map::from( ['a' => 1, 'b' => 2, 'c' => 3] )->except( 'b' );
// ['a' => 1, 'c' => 3]

Map::from( [1 => 'a', 2 => 'b', 3 => 'c'] )->except( [1, 3] );
// [2 => 'b']

explode()

Creates a new map with the string splitted by the delimiter.

public static function explode( string $delimiter , string $string , int $limit = PHP_INT_MAX ) : self

• @param string $delimiter Delimiter character, string or empty string
• @param string $string String to split
• @param int $limit Maximum number of element with the last element containing the rest of the string
• @return self<int|string,mixed> New map with splitted parts

A limit of “0” is treated the same as “1”. If limit is negative, the rest of the string is dropped and not part of the returned map.

This method creates a lazy Map and the string is split after calling another method that operates on the Map contents.

Examples:

Map::explode( ',', 'a,b,c' );
// ['a', 'b', 'c']

Map::explode( '<-->', 'a a<-->b b<-->c c' );
// ['a a', 'b b', 'c c']

Map::explode( '', 'string' );
// ['s', 't', 'r', 'i', 'n', 'g']

Map::explode( '|', 'a|b|c', 2 );
// ['a', 'b|c']

Map::explode( '', 'string', 2 );
// ['s', 't', 'ring']

Map::explode( '|', 'a|b|c|d', -2 );
// ['a', 'b']

Map::explode( '', 'string', -3 );
// ['s', 't', 'r']

filter()

Runs a filter over each element of the map and returns a new map.

public function filter( callable $callback = null ) : self

• @param callable|null $callback Function with (item, key) parameters and returns TRUE/FALSE
• @return self<int|string,mixed> New map

If no callback is passed, all values which are empty, null or false will be removed if their value converted to boolean is FALSE:

(bool) $value === false

The keys in the result map are preserved.

Examples:

Map::from( [null, 0, 1, '', '0', 'a'] )->filter();
// [1, 'a']

Map::from( [2 => 'a', 6 => 'b', 13 => 'm', 30 => 'z'] )->filter( function( $value, $key ) {
    return $key < 10 && $value < 'n';
} );
// ['a', 'b']

find()

Returns the first matching element where the callback returns TRUE.

public function find( \Closure $callback, $default = null, bool $reverse = false )

• @param \Closure $callback Function with (value, key) parameters and returns TRUE/FALSE
• @param mixed $default Default value or exception if the map contains no elements
• @param bool $reverse TRUE to test elements from back to front, FALSE for front to back (default)
• @return mixed|null First matching value, passed default value or an exception

Examples:

Map::from( ['a', 'c', 'e'] )->find( function( $value, $key ) {
    return $value >= 'b';
} );
// 'c'

Map::from( ['a', 'c', 'e'] )->find( function( $value, $key ) {
    return $value >= 'b';
}, null, true );
// 'e' because $reverse = true

Map::from( [] )->find( function( $value, $key ) {
    return $value >= 'b';
}, 'none' );
// 'none'

Map::from( [] )->find( function( $value, $key ) {
    return $value >= 'b';
}, new \Exception( 'error' ) );
// throws \Exception

first()

Returns the first element from the map.

public function first( $default = null )

• @param mixed $default Default value or exception if the map contains no elements
• @return mixed First value of map, (generated) default value or an exception

Examples:

Map::from( ['a', 'b'] )->first();
// 'a'

Map::from( [] )->first( 'x' );
// 'x'

Map::from( [] )->first( new \Exception( 'error' ) );
// throws \Exception

Map::from( [] )->first( function() { return rand(); } );
// random integer

firstKey()

Returns the first key from the map.

public function firstKey()

• @return mixed First key of map or NULL if empty

Examples:

Map::from( ['a' => 1, 'b' => 2] )->lastKey();
// 'a'

Map::from( [] )->lastKey();
// null

flat()

Creates a new map with all sub-array elements added recursively.

public function flat( int $depth = null ) : self

• @param int|null $depth Number of levels to flatten multi-dimensional arrays
• @return self<int|string,mixed> New map with all sub-array elements added into it recursively, up to the specified depth

The keys are not preserved and the new map elements will be numbered from 0-n. A value smaller than 1 for depth will return the same map elements indexed from 0-n. Flattening does also work if elements implement the “Traversable” interface (which the Map object does).

This method is similar than collapse() but doesn’t replace existing elements. Keys are NOT preserved using this method!

Examples:

Map::from( [[0, 1], [2, 3]] )->flat();
// [0, 1, 2, 3]

Map::from( [[0, 1], [[2, 3], 4]] )->flat();
// [0, 1, 2, 3, 4]

Map::from( [[0, 1], [[2, 3], 4]] )->flat( 1 );
// [0, 1, [2, 3], 4]

Map::from( [[0, 1], Map::from( [[2, 3], 4] )] )->flat();
// [0, 1, 2, 3, 4]

flip()

Exchanges the keys with their values and vice versa.

public function flip() : self

• @return self<int|string,mixed> New map with keys as values and values as keys

Examples:

Map::from( ['a' => 'X', 'b' => 'Y'] )->flip();
// ['X' => 'a', 'Y' => 'b']

float()

Returns an element by key and casts it to float if possible.

public function float( $key, $default = 0.0 ) : float

• @param int|string $key Key or path to the requested item
• @param mixed $default Default value if key isn’t found (will be casted to float)
• @return float Value from map or default value

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( ['a' => true] )->float( 'a' );
// 1.0 (casted to float)

Map::from( ['a' => 1] )->float( 'a' );
// 1.0 (casted to float)

Map::from( ['a' => '1.1'] )->float( 'a' );
// 1.1 (casted to float)

Map::from( ['a' => '10'] )->float( 'a' );
// 10.0 (casted to float)

Map::from( ['a' => ['b' => ['c' => 1.1]]] )->float( 'a/b/c' );
// 1.1

Map::from( [] )->float( 'c', function() { return 1.1; } );
// 1.1

Map::from( [] )->float( 'a', 1 );
// 1.0 (default value used)

Map::from( [] )->float( 'a' );
// 0.0

Map::from( ['b' => ''] )->float( 'b' );
// 0.0 (casted to float)

Map::from( ['a' => 'abc'] )->float( 'a' );
// 0.0 (casted to float)

Map::from( ['b' => null] )->float( 'b' );
// 0.0 (null is not scalar)

Map::from( ['b' => [true]] )->float( 'b' );
// 0.0 (arrays are not scalar)

Map::from( ['b' => '#resource'] )->float( 'b' );
// 0.0 (resources are not scalar)

Map::from( ['b' => new \stdClass] )->float( 'b' );
// 0.0 (objects are not scalar)

Map::from( [] )->float( 'c', new \Exception( 'error' ) );
// throws exception

from()

Creates a new map instance if the value isn’t one already.

public static function from( $elements = [] ) : self

• @param mixed $elements List of elements or single value
• @return self<int|string,mixed> New map

Examples:

// array
Map::from( [] );

// null
Map::from( null );

// scalar
Map::from( 'a' );

// object
Map::from( new \stdClass() );

// map object
Map::from( new Map() );

// iterable object
Map::from( new ArrayObject() );

// closure evaluated lazily
Map::from( function() {
    return [];
} );

fromJson()

Creates a new map instance from a JSON string.

public static function fromJson( string $json, int $options = JSON_BIGINT_AS_STRING ) : self

• @param int $options Combination of JSON_* constants
• @return self<int|string,mixed> New map from decoded JSON string
• @throws \RuntimeException If the passed JSON string is invalid

There are several options available for decoding the JSON string which are described in the PHP json_decode() manual. The parameter can be a single JSON_* constant or a bitmask of several constants combine by bitwise OR (|), e.g.:

This method creates a lazy Map and the string is decoded after calling another method that operates on the Map contents. Thus, the exception in case of an error isn’t thrown immediately but after calling the next method.

JSON_BIGINT_AS_STRING|JSON_INVALID_UTF8_IGNORE

Examples:

Map::fromJson( '["a", "b"]' );
// ['a', 'b']

Map::fromJson( '{"a": "b"}' );
// ['a' => 'b']

Map::fromJson( '""' );
['']

get()

Returns an element from the map by key.

public function get( $key, $default = null )

• @param int|string $key Key or path to the requested item
• @param mixed $default Default value if no element matches
• @return mixed Value from map or default value

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( ['a' => 'X', 'b' => 'Y'] )->get( 'a' );
// 'X'

Map::from( ['a' => 'X', 'b' => 'Y'] )->get( 'c', 'Z' );
// 'Z'

Map::from( ['a' => ['b' => ['c' => 'Y']]] )->get( 'a/b/c' );
// 'Y'

Map::from( [] )->get( 'c', new \Exception( 'error' ) );
// throws \Exception

Map::from( [] )->get( 'c', function() { return rand(); } );
// random integer

getIterator()

Returns an iterator for the elements.

public function getIterator() : \ArrayIterator

• @return \Iterator Over map elements

This method will be used by e.g. foreach() to loop over all entries.

Examples:

foreach( Map::from( ['a', 'b'] ) as $value ) {
    // ...
}

grep()

Returns only items which matches the regular expression.

public function grep( string $pattern, int $flags = 0 ) : self

• @param string $pattern Regular expression pattern, e.g. “/ab/”
• @param int $flags PREG_GREP_INVERT to return elements not matching the pattern
• @return self<int|string,mixed> New map containing only the matched elements

All items are converted to string first before they are compared to the regular expression. Thus, fractions of “.0” will be removed in float numbers which may result in unexpected results. The keys are preserved using this method.

Examples:

Map::from( ['ab', 'bc', 'cd'] )->grep( '/b/' );
// ['ab', 'bc']

Map::from( ['ab', 'bc', 'cd'] )->grep( '/a/', PREG_GREP_INVERT );
// ['bc', 'cd']

Map::from( [1.5, 0, 1.0, 'a'] )->grep( '/^(\d+)?\.\d+$/' );
// [1.5]
// float 1.0 is converted to string "1"

groupBy()

Groups associative array elements or objects by the passed key or closure.

public function groupBy( $key ) : self

• @param \Closure|string|int $key Closure function with (item, idx) parameters returning the key or the key itself to group by
• @return self<int|string,mixed> New map with elements grouped by the given key

Instead of overwriting items with the same keys like to the col() method does, groupBy() keeps all entries in sub-arrays. It’s preserves the keys of the orignal map entries too.

Examples:

$list = [
    10 => ['aid' => 123, 'code' => 'x-abc'],
    20 => ['aid' => 123, 'code' => 'x-def'],
    30 => ['aid' => 456, 'code' => 'x-def']
];

Map::from( $list )->groupBy( 'aid' );
/*
[
    123 => [
        10 => ['aid' => 123, 'code' => 'x-abc'],
        20 => ['aid' => 123, 'code' => 'x-def']
    ],
    456 => [
        30 => ['aid' => 456, 'code' => 'x-def']
    ]
]
*/

Map::from( $list )->groupBy( function( $item, $key ) {
    return substr( $item['code'], -3 );
} );
/*
[
    'abc' => [
        10 => ['aid' => 123, 'code' => 'x-abc']
    ],
    'def' => [
        20 => ['aid' => 123, 'code' => 'x-def'],
        30 => ['aid' => 456, 'code' => 'x-def']
    ]
]
*/

In case the passed key doesn’t exist in one or more items, these items are stored in a sub-array using an empty string as key:

$list = [
    10 => ['aid' => 123, 'code' => 'x-abc'],
    20 => ['aid' => 123, 'code' => 'x-def'],
    30 => ['aid' => 456, 'code' => 'x-def']
];

Map::from( $list )->groupBy( 'xid' );
/*
[
    '' => [
        10 => ['aid' => 123, 'code' => 'x-abc'],
        20 => ['aid' => 123, 'code' => 'x-def'],
        30 => ['aid' => 456, 'code' => 'x-def']
    ]
]
*/

has()

Determines if a key or several keys exists in the map.

public function has( $key ) : bool

• @param array<int|string<|int|string $key Key or path to the requested item
• @return bool TRUE if key is available in map, FALSE if not

If several keys are passed as array, all keys must exist in the map to return TRUE.

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( ['a' => 'X', 'b' => 'Y'] )->has( 'a' );
// true

Map::from( ['a' => 'X', 'b' => 'Y'] )->has( ['a', 'b'] );
// false

Map::from( ['a' => ['b' => ['c' => 'Y']]] )->has( 'a/b/c' );
// true

Map::from( ['a' => 'X', 'b' => 'Y'] )->has( 'c' );
// false

Map::from( ['a' => 'X', 'b' => 'Y'] )->has( ['a', 'c'] );
// false

Map::from( ['a' => 'X', 'b' => 'Y'] )->has( 'X' );
// false

if()

Executes callbacks depending on the condition.

public function if( $condition, \Closure $then, \Closure $else = null ) : self

• @param \Closure|bool $condition Boolean or function with (map) parameter returning a boolean
• @param \Closure $then Function with (map) parameter
• @param \Closure|null $else Function with (map) parameter (optional)
• @return self<int|string,mixed> New map for fluid interface

If callbacks for “then” and/or “else” are passed, these callbacks will be executed and their returned value is passed back within a Map object. In case no “then” or “else” closure is given, the method will return the same map object if the condition is true or an empty map object if it’s false.

Examples:

Map::from( ['a' => 1, 'b' => 0] )->if(
    'a' == 'b',
    function( Map $_ ) { echo "then"; }
);
// no output

Map::from( ['a' => 1, 'b' => 0] )->if(
    function( Map $map ) { return $map->has( 'a' ); },
    function( Map $_ ) { echo "then"; },
    function( Map $_ ) { echo "else"; }
);
// then

Map::from( ['a' => 1, 'b' => 0] )->if(
    fn( Map $map ) => $map->has( 'c' ),
    function( Map $_ ) { echo "then"; },
    function( Map $_ ) { echo "else"; }
);
// else

Map::from( ['a', 'b'] )->if( true, function( $map ) {
    return $map->push( 'c' );
} );
// ['a', 'b', 'c']

Map::from( ['a', 'b'] )->if( false, null, function( $map ) {
  return $map->pop();
} );
// ['b']

Since PHP 7.4, you can also pass arrow function like fn($map) => $map->has('c') (a short form for anonymous closures) as parameters. The automatically have access to previously defined variables but can not modify them. Also, they can not have a void return type and must/will always return something. Details about PHP arrow functions

ifAny()

• Executes callbacks depending if the map contains elements or not.

public function ifAny( \Closure $then = null, \Closure $else = null ) : self

• @param \Closure|null $then Function with (map, condition) parameter (optional)
• @param \Closure|null $else Function with (map, condition) parameter (optional)
• @return self<int|string,mixed> New map for fluid interface

If callbacks for “then” and/or “else” are passed, these callbacks will be executed and their returned value is passed back within a Map object. In case no “then” or “else” closure is given, the method will return the same map object.

Examples:

Map::from( ['a'] )->ifAny( function( $map ) {
  $map->push( 'b' );
} );
// ['a', 'b']

Map::from( [] )->ifAny( null, function( $map ) {
  return $map->push( 'b' );
} );
// ['b']

Map::from( ['a'] )->ifAny( function( $map ) {
  return 'c';
} );
// ['c']

Since PHP 7.4, you can also pass arrow function like fn($map) => $map->has('c') (a short form for anonymous closures) as parameters. The automatically have access to previously defined variables but can not modify them. Also, they can not have a void return type and must/will always return something. Details about PHP arrow functions

ifEmpty()

• Executes callbacks depending if the map is empty or not.

public function ifEmpty( \Closure $then = null, \Closure $else = null ) : self

• @param \Closure|null $then Function with (map, condition) parameter (optional)
• @param \Closure|null $else Function with (map, condition) parameter (optional)
• @return self<int|string,mixed> New map for fluid interface

If callbacks for “then” and/or “else” are passed, these callbacks will be executed and their returned value is passed back within a Map object. In case no “then” or “else” closure is given, the method will return the same map object.

Examples:

Map::from( [] )->ifEmpty( function( $map ) {
    $map->push( 'a' );
} );
// ['a']

Map::from( ['a'] )->ifEmpty( null, function( $map ) {
    return $map->push( 'b' );
} );
// ['a', 'b']

Since PHP 7.4, you can also pass arrow function like fn($map) => $map->has('c') (a short form for anonymous closures) as parameters. The automatically have access to previously defined variables but can not modify them. Also, they can not have a void return type and must/will always return something. Details about PHP arrow functions

implements()

Tests if all entries in the map are objects implementing the given interface.

public function implements( string $interface, $throw = false ) : bool

• @param string $interface Name of the interface that must be implemented
• @param \Throwable|bool $throw Passing TRUE or an exception name will throw the exception instead of returning FALSE
• @return bool TRUE if all entries implement the interface or FALSE if at least one doesn’t
• @throws \UnexpectedValueException|\Throwable If one entry doesn’t implement the interface

Examples:

Map::from( [new Map(), new Map()] )->implements( '\Countable' );
// true

Map::from( [new Map(), new \stdClass()] )->implements( '\Countable' );
// false

Map::from( [new Map(), 123] )->implements( '\Countable' );
// false

Map::from( [new Map(), 123] )->implements( '\Countable', true );
// throws \UnexpectedValueException

Map::from( [new Map(), 123] )->implements( '\Countable', '\RuntimeException' );
// throws \RuntimeException

in()

Tests if the passed element or elements are part of the map.

public function in( $element, bool $strict = false ) : bool

• @param mixed|array $element Element or elements to search for in the map
• @param bool $strict TRUE to check the type too, using FALSE ‘1’ and 1 will be the same
• @return bool TRUE if all elements are available in map, FALSE if not

Examples:

Map::from( ['a', 'b'] )->in( 'a' );
// true

Map::from( ['a', 'b'] )->in( ['a', 'b'] );
// true

Map::from( ['a', 'b'] )->in( 'x' );
// false

Map::from( ['a', 'b'] )->in( ['a', 'x'] );
// false

Map::from( ['1', '2'] )->in( 2, true );
// false

includes()

Tests if the passed element or elements are part of the map (alias).

public function includes( $element, bool $strict = false ) : bool

• @param mixed|array $element Element or elements to search for in the map
• @param bool $strict TRUE to check the type too, using FALSE ‘1’ and 1 will be the same
• @return bool TRUE if all elements are available in map, FALSE if not

This method is an alias for in(). For performance reasons, in() should be preferred because it uses one method call less than includes().

See also:

• in() - Underlying method with same parameters and return value but better performance

index()

Returns the numerical index of the given key.

public function index( $value ) : ?int

• @param \Closure|string|int $value Key to search for or function with (key) parameters return TRUE if key is found
• @return int|null Position of the found value (zero based) or NULL if not found

Examples:

Map::from( [4 => 'a', 8 => 'b'] )->index( '8' );
// 1

Map::from( [4 => 'a', 8 => 'b'] )->index( function( $key ) {
    return $key == '8';
} );
// 1

Both examples will return “1” because the value “b” is at the second position and the returned index is zero based so the first item has the index “0”.

insertAfter()

Inserts the value or values after the given element.

public function insertAfter( $element, $value ) : self

• @param mixed $element Element after the value is inserted
• @param mixed $value Element or list of elements to insert
• @return self<int|string,mixed> Updated map for fluid interface

Numerical array indexes are not preserved.

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertAfter( 'foo', 'baz' );
// ['a' => 'foo', 0 => 'baz', 'b' => 'bar']

Map::from( ['foo', 'bar'] )->insertAfter( 'foo', ['baz', 'boo'] );
// ['foo', 'baz', 'boo', 'bar']

Map::from( ['foo', 'bar'] )->insertAfter( null, 'baz' );
// ['foo', 'bar', 'baz']

insertAt()

Inserts the item at the given position in the map.

public function insertAt( int $pos, $element, $key = null ) : self

• @param int $pos Position the element it should be inserted at
• @param mixed $element Element to be inserted
• @param mixed|null $key Element key or NULL to assign an integer key automatically
• @return self<int|string,mixed> Updated map for fluid interface

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertAt( 0, 'baz' );
// [0 => 'baz', 'a' => 'foo', 'b' => 'bar']

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertAt( 1, 'baz', 'c' );
// ['a' => 'foo', 'c' => 'baz', 'b' => 'bar']

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertAt( 5, 'baz' );
// ['a' => 'foo', 'b' => 'bar', 'c' => 'baz']

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertAt( -1, 'baz', 'c' );
// ['a' => 'foo', 'c' => 'baz', 'b' => 'bar']

insertBefore()

Inserts the value or values before the given element.

public function insertBefore( $element, $value ) : self

• @param mixed $element Element before the value is inserted
• @param mixed $value Element or list of elements to insert
• @return self<int|string,mixed> Updated map for fluid interface

Numerical array indexes are not preserved.

Examples:

Map::from( ['a' => 'foo', 'b' => 'bar'] )->insertBefore( 'bar', 'baz' );
// ['a' => 'foo', 0 => 'baz', 'b' => 'bar']

Map::from( ['foo', 'bar'] )->insertBefore( 'bar', ['baz', 'boo'] );
// ['foo', 'baz', 'boo', 'bar']

Map::from( ['foo', 'bar'] )->insertBefore( null, 'baz' );
// ['foo', 'bar', 'baz']

inString()

Tests if the passed value or value are part of the strings in the map.

This method is deprecated in favor of the multi-byte aware strContains() method.

public function inString( $value, bool $case = true ) : bool

• @param array|string $value Value or values to compare the map elements, will be casted to string type
• @param bool $case TRUE if comparison is case sensitive, FALSE to ignore upper/lower case
• @return bool TRUE If at least one element matches, FALSE if value is not in any string of the map

All scalar values (bool, float, int and string) are casted to string values before comparing to the given value. Non-scalar values in the map are ignored.

Examples:

Map::from( ['abc'] )->inString( 'c' );
// true ('abc' contains 'c')

Map::from( ['abc'] )->inString( 'bc' );
// true ('abc' contains 'bc')

Map::from( [12345] )->inString( '23' );
// true ('12345' contains '23')

Map::from( [123.4] )->inString( 23.4 );
// true ('123.4' contains '23.4')

Map::from( [12345] )->inString( false );
// true ('12345' contains '')

Map::from( [12345] )->inString( true );
// true ('12345' contains '1')

Map::from( [false] )->inString( false );
// true  ('' contains '')

Map::from( ['abc'] )->inString( '' );
// true ('abc' contains '')

Map::from( [''] )->inString( false );
// true ('' contains '')

Map::from( ['abc'] )->inString( 'BC', false );
// true ('abc' contains 'BC' when case-insentive)

Map::from( ['abc', 'def'] )->inString( ['de', 'xy'] );
// true ('def' contains 'de')

Map::from( ['abc', 'def'] )->inString( ['E', 'x'] );
// false (doesn't contain "E" when case sensitive)

Map::from( ['abc', 'def'] )->inString( 'E' );
// false (doesn't contain "E" when case sensitive)

Map::from( [23456] )->inString( true );
// false ('23456' doesn't contain '1')

Map::from( [false] )->inString( 0 );
// false ('' doesn't contain '0')

int()

Returns an element by key and casts it to integer if possible.

public function int( $key, $default = 0 ) : int

• @param int|string $key Key or path to the requested item
• @param mixed $default Default value if key isn’t found (will be casted to int)
• @return int Value from map or default value

This does also work to map values from multi-dimensional arrays by passing the keys of the arrays separated by the delimiter (“/” by default), e.g. key1/key2/key3 to get val from ['key1' => ['key2' => ['key3' => 'val']]]. The same applies to public properties of objects or objects implementing __isset() and __get() methods.

Examples:

Map::from( ['a' => true] )->int( 'a' );
// 1

Map::from( ['a' => '1'] )->int( 'a' );
// 1 (casted to integer)

Map::from( ['a' => 1.1] )->int( 'a' );
// 1 (casted to integer)

Map::from( ['a' => '10'] )->int( 'a' );
// 10 (casted to integer)

Map::from( ['a' => ['b' => ['c' => 1]]] )->int( 'a/b/c' );
// 1

Map::from( [] )->int( 'c', function() { return rand( 1, 1 ); } );
// 1

Map::from( [] )->int( 'a', 1 );
// 1 (default value used)

Map::from( [] )->int( 'a' );
// 0

Map::from( ['b' => ''] )->int( 'b' );
// 0 (casted to integer)

Map::from( ['a' => 'abc'] )->int( 'a' );
// 0 (casted to integer)

Map::from( ['b' => null] )->int( 'b' );
// 0 (null is not scalar)

Map::from( ['b' => [true]] )->int( 'b' );
// 0 (arrays are not scalar)

Map::from( ['b' => '#resource'] )->int( 'b' );
// 0 (resources are not scalar)

Map::from( ['b' => new \stdClass] )->int( 'b' );
// 0 (objects are not scalar)

Map::from( [] )->int( 'c', new \Exception( 'error' ) );
// throws exception