基于php中的dateTime排序数组

Question

Array
        (
            [0] => Array
                (
                    [dateTime] => 2011-10-18 0:0:00
                    [chanl1] => 20.7
                    [chanl2] => 45.4
                    [chanl3] => 
                )

            [1] => Array
                (
                    [dateTime] => 2011-10-18 0:15:00
                    [chanl1] => 20.7
                    [chanl2] => 45.4
                    [chanl3] => 
                )


            [2] => Array
                (
                    [dateTime] => 2011-10-18 00:14:00
                    [chanl1] => 20.7
                    [chanl2] => 33.8
                    [chanl3] => 
                )

            [3] => Array
                (
                    [dateTime] => 2011-10-18 00:29:00
                    [chanl1] => 20.6
                    [chanl2] => 33.9
                    [chanl3] => 
                )

我想基于[dateTime]对上面的数组进行排序,最终的输出应该是:

Array
        (
            [0] => Array
                (
                    [dateTime] => 2011-10-18 0:0:00
                    [chanl1] => 20.7
                    [chanl2] => 45.4
                    [chanl3] => 
                )

            [1] => Array
                (
                    [dateTime] => 2011-10-18 00:14:00
                    [chanl1] => 20.7
                    [chanl2] => 33.8
                    [chanl3] => 
                )

            [2] => Array
                (
                    [dateTime] => 2011-10-18 0:15:00
                    [chanl1] => 20.7
                    [chanl2] => 45.4
                    [chanl3] => 
                )            

            [3] => Array
                (
                    [dateTime] => 2011-10-18 00:29:00
                    [chanl1] => 20.6
                    [chanl2] => 33.9
                    [chanl3] => 
                )

有谁知道怎么做？谢谢!

Answer 1

使用自定义比较器的usort()功能:

$arr = array(...);

usort($arr, function($a, $b) {
  $ad = new DateTime($a['dateTime']);
  $bd = new DateTime($b['dateTime']);

  if ($ad == $bd) {
    return 0;
  }

  return $ad < $bd ? -1 : 1;
});

日期时间类已重载比较运算符(<,>,==).

Answer 2

使用uasort()自定义排序回调应该这样做:

function cmp($a, $b) {
  if ($a['dateTime'] == $b['dateTime']) {
    return 0;
  }

  return ($a['dateTime'] < $b['dateTime']) ? -1 : 1;
}

uasort($arr, 'cmp');

uasort()保留数组的键,usort()如果不需要,可以使用它.

Answer 3

为了提高性能,使用array_multisort的方法非常有效:

$ord = array();
foreach ($array as $key => $value){
    $ord[] = strtotime($value['dateTime']);
}
array_multisort($ord, SORT_ASC, $array);
print_r($array);

Answer 4

使用宇宙飞船运算符对 DateTime 对象进行简单排序：

$list = [
    new DateTime('yesterday'),
    new DateTime('today'),
    new DateTime('1 week ago'),
];

uasort($list, function ($a, $b) {
    return $a <=> $b;
});

var_dump($list);

Answer 5

对于 php 数组和对象，此示例有助于排序...

对于日期时间降序：

usort($response_data['callback'], function($a, $b) {
   return strcasecmp(strtotime($b->view_date), strtotime($a->view_date));
});

对于日期时间升序：

usort($response_data['callback'], function($a, $b) {
   return strtotime($a->view_date) - strtotime($b->view_date);
});