在PHP中对usort中的类似结果进行排序

我知道这段代码是按最新开始时间对活动数组进行排序的，并且只显示循环中最先出现的具有相同日期的活动

foreach ($activity_array AS $k => $v):
......

usort($v['activity'], function ($a, $b) {
$ad = new DateTime($a['start']);
$bd = new DateTime($b['start']);
if ($ad == $bd) {
return 0;
}
return $ad < $bd ? -1 : 1;
});

如：

|  Activity  |  Start         |   Venue   |
+------------+----------------+-----------+
| Activity A | 22/10/17 08.30 | Floor 1   |
| Activity X | 22/10/17 09.30 | Floor 2   |
| Activity B | 22/10/17 10.30 | Hall 1    |
| Activity C | 22/10/17 10.30 | Hall 2    |
| Activity D | 22/10/17 10.30 | Hall 3    |

---

当开始时间相同时，您可以再次检查场地

foreach ($activity_array AS $k => $v):
......

usort($v['activity'], function ($a, $b) {
$ad = new DateTime($a['start']);
$bd = new DateTime($b['start']);
if ($ad == $bd) {

    $venue1 = $a['venue'];
    $venue2 = $b['venue'];
    return strcmp($venue1, $venue2);
}
return $ad < $bd ? -1 : 1;
});

foreach（$k=>v的活动数组）：
......
usort（$v['activity']，函数（$a，$b）{
$ad=新日期时间（$a['start']）；
$bd=新日期时间（$b['start']）；
如果（$ad=$bd）{
$venue1=$a[‘场地’]；
$venue2=$b[‘场地’]；
返回strcmp（$venue1，$venue2）；
}
返回$ad<$bd？-1:1；
});

这是您的解决方案

$array = array(
        array('activity' => 'Activity A', 'start' => '22/10/17 08.30', 'venue' => 'Floor 1'),
        array('activity' => 'Activity D', 'start' => '22/10/17 10.30', 'venue' => 'Hall 3'),
        array('activity' => 'Activity B', 'start' => '22/10/17 10.30', 'venue' => 'Hall 1'),
        array('activity' => 'Activity C', 'start' => '22/10/17 10.30', 'venue' => 'Hall 2'),
        array('activity' => 'Activity X', 'start' => '22/10/17 09.30', 'venue' => 'Floor 2')
);  //Your Array
usort($array,"cmp");
function cmp($a, $b){
    if ($a["venue"] == $b["venue"]) {
        return 0;
    }
    return ($a["venue"] < $b["venue"]) ? -1 : 1;
}

---

（$venue1-$venue2）；==第一层-第二层

我认为这不会产生任何结果谢谢@B.Desai，我不知道这个函数存在。问题很好。+1

$array = array(
        array('activity' => 'Activity A', 'start' => '22/10/17 08.30', 'venue' => 'Floor 1'),
        array('activity' => 'Activity D', 'start' => '22/10/17 10.30', 'venue' => 'Hall 3'),
        array('activity' => 'Activity B', 'start' => '22/10/17 10.30', 'venue' => 'Hall 1'),
        array('activity' => 'Activity C', 'start' => '22/10/17 10.30', 'venue' => 'Hall 2'),
        array('activity' => 'Activity X', 'start' => '22/10/17 09.30', 'venue' => 'Floor 2')
);  //Your Array
usort($array,"cmp");
function cmp($a, $b){
    if ($a["venue"] == $b["venue"]) {
        return 0;
    }
    return ($a["venue"] < $b["venue"]) ? -1 : 1;
}

Array
(
[0] => Array
    (
        [activity] => Activity A
        [start] => 22/10/17 08.30
        [venue] => Floor 1
    )

[1] => Array
    (
        [activity] => Activity X
        [start] => 22/10/17 09.30
        [venue] => Floor 2
    )

[2] => Array
    (
        [activity] => Activity B
        [start] => 22/10/17 10.30
        [venue] => Hall 1
    )

[3] => Array
    (
        [activity] => Activity C
        [start] => 22/10/17 10.30
        [venue] => Hall 2
    )

[4] => Array
    (
        [activity] => Activity D
        [start] => 22/10/17 10.30
        [venue] => Hall 3
    )

)