PHP排序多维数组由项目数
问题描述：
我有一个数组，如：
Array
(
[DEF] => Array
(
[0] => Array
(
[type] => 1
[id] => 1212
[name] => Jane Doe
[current] => 1
)
[1] => Array
(
[type] => 1
[id] => 3123121
[name] => Door
[current] =>
)
)
[ABC] => Array
(
[0] => Array
(
[type] => 1
[id] => 1234
[name] => John Doe
[current] =>
)
)
[WW] => Array
(
[0] => Array
(
[type] => 1
[id] => 1212
[name] => Jane Doe
[current] => 1
)
[1] => Array
(
[type] => 1
[id] => 3123121
[name] => Door
[current] =>
)
[2] => Array
(
[type] => 1
[id] => 64646
[name] => Floor
[current] =>
)
)
)
和我想排序这个数组由数内数组项（即第一大部分项目）的递减（COUNT（）），这样我就有这个数组：
And I want to sort this array by number ( count() ) of inner-array items descending (i.e. most items first), so I will have this array:
Array
(
[WW] => Array
(
[0] => Array
(
[type] => 1
[id] => 1212
[name] => Jane Doe
[current] => 1
)
[1] => Array
(
[type] => 1
[id] => 3123121
[name] => Door
[current] =>
)
[2] => Array
(
[type] => 1
[id] => 64646
[name] => Floor
[current] =>
)
)
[DEF] => Array
(
[0] => Array
(
[type] => 1
[id] => 1212
[name] => Jane Doe
[current] => 1
)
[1] => Array
(
[type] => 1
[id] => 3123121
[name] => Door
[current] =>
)
)
[ABC] => Array
(
[0] => Array
(
[type] => 1
[id] => 1234
[name] => John Doe
[current] =>
)
)
)
任何人都可以提出一个有效的方式来做到这一点？谢谢你。
Can anyone suggest an efficient way to do so? Thanks.
答
使用 uksort 一>：
uksort($array, function($a, $b) { return count($b) - count($a); });
使用在array_multisort ：
array_multisort(array_map('count', $array), SORT_DESC, $array);
使用PHP＆LT; 5.3：
With PHP < 5.3:
function sort_cb($a, $b) {
return count($b) - count($a);
}
uksort($array, 'sort_cb');