php Yii2.0 ArrayHelper::map() 用法剖析

$from

$to

$group

$array = [
['id' => '123', 'name' => 'aaa', 'class' => 'x'],
['id' => '124', 'name' => 'bbb', 'class' => 'x'],
['id' => '345', 'name' => 'ccc', 'class' => 'y'],
];

$result = ArrayHelper::map($array, 'id', 'name');

[
'123' => 'aaa',
'124' => 'bbb',
'345' => 'ccc',
]

$result = ArrayHelper::map($array, 'id', 'name', 'class');

[
'x' => [
'123' => 'aaa',
'124' => 'bbb',
],
'y' => [
'345' => 'ccc',
],
]

/**
* @paramarray $array
* @param string|Closure $from
* @param string|Closure $to
* @param string|Closure $group
* @return array
*/
public static function map($array, $from, $to, $group = null)
{
$result = [];
foreach ($array as $element) {
$key = static:: getValue($element, $from);
$value = static:: getValue($element, $to);
if ($group !== null) {
$result[ static:: getValue($element, $group)][$key] = $value;
} else {
$result[$key] = $value;
}
}
return $result;
}