JavaScript相当于PHP $ array [$ i] []

Question

我在JavaScript中创建多维数组时遇到问题.

PHP代码如下所示:

<?php
$matches = array(1, 2, 3, 4, 4, 4, 6, 6, 2, 3);

foreach($matches as $match) {

     $levels[$match][] = $match;
}

print_r($levels);
?>

$ level的print_r:

levels[1][0] = 1
levels[2][0] = 2
levels[3][0] = 3
levels[4][0] = 4
levels[4][1] = 4
levels[4][2] = 4
levels[6][0] = 6
levels[6][1] = 6
levels[2][1] = 2
levels[3][1] = 3

我在JavaScript中创建相同的数组时遇到问题.

<script>
var levels = [];

$([1, 2, 3, 4, 4, 4, 6, 6, 2, 3]).each(function(key, value) {

     levels[value][] = value;
});
</script>

有人可以帮助我在JavaScript中创建相同的数组吗？

Answer 1

如果没有,JavaScript不会神奇地创建一个数组.你必须自己创建它.所以它会是这样的

$([1, 2, 3, 4, 4, 4, 6, 6, 2, 3]).each(function(key, value) {
    if (levels[value] == null) {
        levels[value] = [];
    }
    levels[value].push(value);
});

详细了解阵列.