php二维数组怎么根据某个字段排序

可以使用array_multisort()函数来根据某个字段对二维数组进行排序。

假设有以下二维数组：

$users = array(    array('name' => 'John', 'age' => 25, 'city' => 'New York'),    array('name' => 'Amy', 'age' => 30, 'city' => 'Los Angeles'),    array('name' => 'Peter', 'age' => 20, 'city' => 'Chicago'));

如果要根据age字段对数组进行升序排序，可以使用以下代码：

$ages = array_column($users, 'age'); // 提取所有用户的age字段值array_multisort($ages, SORT_ASC, $users); // 根据age字段值进行排序print_r($users);

输出结果为：

Array(    [0] => Array        (            [name] => Peter            [age] => 20            [city] => Chicago        )    [1] => Array        (            [name] => John            [age] => 25            [city] => New York        )    [2] => Array        (            [name] => Amy            [age] => 30            [city] => Los Angeles        ))

如果要根据city字段对数组进行降序排序，可以使用以下代码：

$cities = array_column($users, 'city'); // 提取所有用户的city字段值array_multisort($cities, SORT_DESC, $users); // 根据city字段值进行排序print_r($users);

输出结果为：

Array(    [0] => Array        (            [name] => Amy            [age] => 30            [city] => Los Angeles        )    [1] => Array        (            [name] => Peter            [age] => 20            [city] => Chicago        )    [2] => Array        (            [name] => John            [age] => 25            [city] => New York        ))