PHP -通过根据值索引对多维数组的键进行分组来复制多维数组

<?php
// 原始多维数组
$originalArray = array(
    array('name' => 'John', 'age' => 25),
    array('name' => 'Jane', 'age' => 30),
    array('name' => 'Bob', 'age' => 25),
    array('name' => 'Alice', 'age' => 30)
);

// 通过年龄进行分组的新多维数组
$newArray = array();
foreach ($originalArray as $item) {
    $age = $item['age'];
    if (!isset($newArray[$age])) {
        $newArray[$age] = array();
    }
    $newArray[$age][] = $item;
}

// 输出新多维数组
print_r($newArray);
?>

Array
(
    [25] => Array
        (
            [0] => Array
                (
                    [name] => John
                    [age] => 25
                )

            [1] => Array
                (
                    [name] => Bob
                    [age] => 25
                )

        )

    [30] => Array
        (
            [0] => Array
                (
                    [name] => Jane
                    [age] => 30
                )

            [1] => Array
                (
                    [name] => Alice
                    [age] => 30
                )

        )

)