php - 如何通过比较删除特定索引

Question

我想通过比较删除一些索引，但这并不容易

第一个我们的 php 版本是 5例如我的结果是这样的它是由 json_encode 回显的，它是数组并且数据是动态的

[
        {
            "idx": "1",
            "mom_member_idx": "1",
            "teacher_member_idx": "2",
            "care_start_datetime": "2019-09-09 08:30:00",
         },

        {
            "idx": "2",
            "mom_member_idx": "1",
            "teacher_member_idx": "2",
            "care_start_datetime": "2019-09-10 08:30:00",
         },
         {
            "idx": "3",
            "mom_member_idx": "2",
            "teacher_member_idx": "2",
            "care_start_datetime": "2019-09-09 08:30:00",
         }

]

我想得到这样的结果，与最新的比较并取消设置

[
        {
            "idx": "1",
            "mom_member_idx": "1",
            "teacher_member_idx": "2",
            "care_start_datetime": "2019-09-09 08:30:00",
         },
         {
            "idx": "3",
            "mom_member_idx": "2",
            "teacher_member_idx": "2",
            "care_start_datetime": "2019-09-09 08:30:00",
         }

]

我试过了，但是不行

while ($r = mysqli_fetch_assoc($chat_list)) {
    $dbdata[] = $r;
}
for($r=0;$r<sizeof($dbdata);$r++){
    if ($dbdata[$r]['mom_member_idx']+$dbdata[$r]['teacher_member_idx']==$dbdata[$r+1]['mom_member_idx']+$dbdata[$r+1]['teacher_member_idx'])
    {
        if($dbdata[$r]['care_start_datetime']<$dbdata[$r+1]['care_start_datetime']){
            unset($dbdata[$r]);
        }else {
            unset($dbdata[$r+1]);
        }
    }
}

Answer 1

首先，将您的 JSON 数组转换为 PHP 数组。然后你可以使用数组索引删除数组元素

$someArray = json_decode($someJSON, true);