通过引用改变多维数组中的值(在PHP中)？

$array = [
    'key1' => [
        'subkey1' => 'value1',
        'subkey2' => 'value2',
    ],
    'key2' => [
        'subkey3' => 'value3',
        'subkey4' => 'value4',
    ],
];

// 通过引用改变多维数组中的值
$newValue = 'new value';
$array['key1']['subkey1'] = &$newValue;

// 输出修改后的数组
print_r($array);

Array
(
    [key1] => Array
        (
            [subkey1] => new value
            [subkey2] => value2
        )

    [key2] => Array
        (
            [subkey3] => value3
            [subkey4] => value4
        )
)