从Json数组中删除一个元素 [英] Remove an element from Json array

问题描述

我将数组内容以json数组的形式存储到数据库中.

I stored my array content in form of json array to database .

格式:["1"，"2"，"3"]

Format: ["1","2","3"]

现在，我从数据库中检索了值，并尝试从同一结构中删除第三个元素"2".

Now i retrieved the value from database and tried to remove the third element "2" from same structure.

我的代码是

$numbers= json_decode($numbers_db,true); //json decode numbers array got from DB
if (($key = array_search(2, $numbers)) !== false) {
                    unset($numbers[$key]);
                 }
                 $numbers_final = json_encode($numbers);

现在我希望$ numbers_final的格式为:["1","3"]

Now i expected $numbers_final to be of the format: ["1","3"]

但是它导致了{"0":"1","2":"3"}

推荐答案

问题是，当您unset()元素时，索引保持不变.在这种情况下，索引1不再存在，因此该数组将转换为对象.

The problem is that when you unset() an element, the indexes are kept intact. In this case, the index 1 doesn't exists anymore so the array is converted into an object.

要强制对数组进行顺序重新索引，您可以执行以下操作:

To force the array to be re-indexed sequentially yo can do something like this:

$numbers_db  = '["1", "2", "3"]';

echo $numbers_db;

$numbers= json_decode($numbers_db,true); //json decode numbers ar

if (($key = array_search(2, $numbers)) !== false) {
    unset($numbers[$key]);
    $numbers = array_values($numbers);
}
$numbers_final = json_encode($numbers);

echo $numbers_final;                 

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