data = [{id: 1, total: 400},{id: 2, total: 100},{id: 3, total: 500},{id: 4, total: 10}]

如何按总数对该数组排序？另外,我尝试使字段总数总计,但失败了.

foreach($data as $val){
  $d[] = $val['total'];
}
return $d;

并得到了这个错误.

Cannot use object of type stdClass as array

解决方法:

尝试使用usort：如果您仍使用PHP 5.2或更早版本,则必须首先定义一个排序函数：

$json = '[{"id": 1, "total": 400}, {"id": 2, "total": 100}, {"id": 3, "total": 500}, {"id": 4, "total": 10}]';

    $myArray = json_decode($json, true);
    function sortByOrder($a, $b)
    {
        return $a['total'] - $b['total'];
    }

    usort($myArray, 'sortByOrder');
    print_r($myArray);

从PHP 5.3开始,您可以使用匿名函数：

usort($myArray, function ($a, $b) {
    return $a['total'] - $b['total'];
});

最后,在PHP 7中,您可以使用“太空飞船操作符”：

usort($myArray, function ($a, $b) {
        return $a['type'] <=> $b['type'];
});

输出：

Array
(
    [0] => Array
        (
            [id] => 4
            [total] => 10
        )

    [1] => Array
        (
            [id] => 2
            [total] => 100
        )

    [2] => Array
        (
            [id] => 1
            [total] => 400
        )

    [3] => Array
        (
            [id] => 3
            [total] => 500
        )

)