小编now*_*w_m的帖子

我有一个 usort() 示例，我添加了一些 echo 语句来查看代码的工作原理：

<?php
function list_cmp($a, $b) {
    global $order;
    echo "\$a=$a, \$b=$b </br>";

    foreach ($order as $key => $value) {
        echo "\$value=$value </br>";
        if ($a == $value) {
            echo "\$a=\$value, returing 0. </br>";
            return 0;
        }
        if ($b == $value) {
            echo "\$b=\$value, returing 1. </br>";
            return 1;
        }
    }
}

$order[0] = 1;
$order[1] = 3;
$order[2] = 4;
$order[3] = 2;

$array[0] = 2;
$array[1] = 1;
$array[2] = 3;
$array[3] = 4;
$array[4] = …