jgdoncel
11/18/2016 - 11:46 AM
PHP : Groups an array by a given key
PHP : Groups an array by a given key
{
"name": "jgdoncel/php-array-group-by",
"description": "Groups an array by a given key.",
"authors": [
{
"name": "Jose García",
"email": "jgdoncel@gmail.com",
"homepage": "https://github.com/jgdoncel"
}
],
"keywords": [
"function"
],
"require": {
"php": ">=5.3.3"
},
"autoload": {
"files": ["Function.Array-Group-By.php"]
}
}Fork of https://gist.github.com/mcaskill/baaee44487653e1afc0d with no short sintax for arrays allowing PHP < 5.4
array_group_by
(PHP 5 >= 5.3.3)
array_group_by — Groups an array by a given key.
Description
array|null array_group_by( array $array, mixed $key1 [, mixed $... ] )
Groups an array into arrays by a given $key, or set of keys, shared between all array members.
Based on Jake Zatecky's array_group_by() function.
This fork offers:
$keyparameter can be a closure
Parameters
$array— The array to have grouping performed on.$key— The key to group or split by. Can be a string, an integer, a float, or a callback.
If the key is a callback, it must return a valid key from the array.string|int callback ( mixed $item )...— Additional keys for grouping the next set of sub-arrays.
Return Values
Returns a multidimensional array, with each dimension containing elements grouped by the passed key(s).
Errors/Exceptions
If $key is not one of the accepted types E_USER_ERROR will be thrown and NULL returned.
Examples
Example #1 array_group_by() example
$records = [
[
"state" => "IN",
"city" => "Indianapolis",
"object" => "School bus"
],
[
"state" => "IN",
"city" => "Indianapolis",
"object" => "Manhole"
],
[
"state" => "IN",
"city" => "Plainfield",
"object" => "Basketball"
],
[
"state" => "CA",
"city" => "San Diego",
"object" => "Light bulb"
],
[
"state" => "CA",
"city" => "Mountain View",
"object" => "Space pen"
]
];
$grouped = array_group_by( $records, "state", "city" );
The above example will output:
Array
(
[IN] => Array
(
[Indianapolis] => Array
(
[0] => Array
(
[state] => IN
[city] => Indianapolis
[object] => School bus
)
[1] => Array
(
[state] => IN
[city] => Indianapolis
[object] => Manhole
)
)
[Plainfield] => Array
(
[0] => Array
(
[state] => IN
[city] => Plainfield
[object] => Basketball
)
)
)
[CA] => Array
(
[San Diego] => Array
(
[0] => Array
(
[state] => CA
[city] => San Diego
[object] => Light bulb
)
)
[Mountain View] => Array
(
[0] => Array
(
[state] => CA
[city] => Mountain View
[object] => Space pen
)
)
)
)
Installation
With Composer
$ composer require mcaskill/php-array-group-by
{
"repositories": [
{
"type": "git",
"url": "https://gist.github.com/***.git"
}
],
"require": {
"jgdoncel/php-array-group-by": "dev-master"
}
}
Without Composer
Why are you not using composer? Download Function.Array-Group-By.php from the gist and save the file into your project path somewhere.
<?php
if ( ! function_exists('array_group_by') ) :
/**
* Groups an array by a given key.
*
* Groups an array into arrays by a given key, or set of keys, shared between all array members.
*
* Based on {@author Jake Zatecky}'s {@link https://github.com/jakezatecky/array_group_by array_group_by()} function.
* This variant allows $key to be closures.
*
* @param array $array The array to have grouping performed on.
* @param mixed $key,... The key to group or split by. Can be a _string_,
* an _integer_, a _float_, or a _callable_.
*
* If the key is a callback, it must return
* a valid key from the array.
*
* ```
* string|int callback ( mixed $item )
* ```
*
* @return array|null Returns a multidimensional array or `null` if `$key` is invalid.
*/
function array_group_by( array $array, $key )
{
if ( ! is_string( $key ) && ! is_int( $key ) && ! is_float( $key ) && ! is_callable( $key ) ) {
trigger_error( 'array_group_by(): The key should be a string, an integer, or a callback', E_USER_ERROR );
return null;
}
$func = ( is_callable( $key ) ? $key : null );
$_key = $key;
// Load the new array, splitting by the target key
$grouped = array();
foreach ( $array as $value ) {
if ( is_callable( $func ) ) {
$key = call_user_func( $func, $value );
} elseif ( is_object( $value ) && isset( $value->{ $_key } ) ) {
$key = $value->{ $_key };
} elseif ( isset( $value[ $_key ] ) ) {
$key = $value[ $_key ];
} else {
continue;
}
$grouped[ $key ][] = $value;
}
// Recursively build a nested grouping if more parameters are supplied
// Each grouped array value is grouped according to the next sequential key
if ( func_num_args() > 2 ) {
$args = func_get_args();
foreach ( $grouped as $key => $value ) {
$params = array_merge( array( $value ), array_slice( $args, 2, func_num_args() ) );
$grouped[ $key ] = call_user_func_array( 'array_group_by', $params );
}
}
return $grouped;
}
endif;