如何在 PHP 中按长度对二维数组进行排序？

Question

我有一个字符串数组，我想按长度降序排序。 但是，它是一个二维数组，我不确定如何实现 function 来满足我的需求。

下面是一个数组示例：

Array
(
  [0] => Array
    (
      [0] => "abc"
      [1] => "def"
      [2] => "1234"
    )

  [1] => Array
    (
      [0] => "ghijkl"
      [1] => "092"
      [2] => "234234"
    )

  [2] => Array
    (
      [0] => "mn"
      [1] => "opq"
      [2] => "67843"
    )
)

我只对子数组中第一项的长度感兴趣。 所以理想情况下它最终看起来像这样：

Array
(
  [0] => Array
    (
      [0] => "ghijkl"
      [1] => "092"
      [2] => "234234"
    )
  [1] => Array
    (
      [0] => "abc"
      [1] => "def"
      [2] => "1234"
    )
  [2] => Array
    (
      [0] => "mn"
      [1] => "opq"
      [2] => "67843"
    )
)

为你能给我的任何帮助干杯。

Answer 1

usort($array, function ($a, $b) { return strlen($b[0]) - strlen($a[0]); });

（使用 PHP 5.3 语法）

Answer 2

<?php

$your_array = array
(
  array
    (
      "abc",
      "def",
      "1234"
    ),

  array
    (
      "ghijkl",
      "092",
      "234234"
    ),
array
    (
      "mn",
      "opq",
      "67843"
    )
);

function customSort(Array $a, Array $b){         
     return strlen($b[0]) - strlen($a[0]);  
}

usort($your_array, 'customSort');
var_dump($your_array);