如何在PHP中的关联数组中更新特定键的值？

Question

我有一个名为的以下关联数组 $data

Array
(
    [0] => Array
        (
            [transaction_user_id] => 359691e27b23f8ef3f8e1c50315cd506
            [transaction_no] => 19500912050218
            [transaction_total_amount] => 589.00
            [transaction_date] => 1335932419
            [transaction_status] => cancelled
        )

    [1] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 36010512050819
            [transaction_total_amount] => 79.00
            [transaction_date] => 1336476696
            [transaction_status] => cancelled
        )

    [2] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 19020512050820
            [transaction_total_amount] => 299.00
            [transaction_date] => 1336476739
            [transaction_status] => cancelled
        )

    [3] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 27050512050821
            [transaction_total_amount] => 79.00
            [transaction_date] => 1336476927
            [transaction_status] => cancelled
        )

    [4] => Array
        (
            [transaction_user_id] => 8e9050a3646c98342b9ba079fba80982
            [transaction_no] => 12070512050822
            [transaction_total_amount] => 129.00
            [transaction_date] => 1336477032
            [transaction_status] => cancelled
        )

)

我想将key的值转换[transaction_date]为用户可读格式(即mm/dd/yyyy).为此,我在一个返回整个数组的函数中编写了以下代码:

 foreach($data as $value)
        {
            $value[transaction_date]=date('d/m/Y',$value[transaction_date]);
        }

    return $data;

我的问题是我得到了相同的数组而没有改变[transaction_date]所有数组元素的值.实际上,[transaction_date]预计将返回具有更新值的数组.任何人都可以帮我解决这个问题吗？提前致谢.

Answer 1

将foreach更改为类似的内容,$data在执行操作后,您不会将数据分配回返回变量.

foreach($data as $key => $value)
{
  $data[$key]['transaction_date'] = date('d/m/Y',$value['transaction_date']);
}

键盘演示.

Answer 2

这也会奏效!

foreach($data as &$value) {
  $value['transaction_date'] = date('d/m/Y', $value['transaction_date']);
}

是的替代品!

Answer 3

PHP array_walk()函数专门用于改变数组.

试试这个:

array_walk ( $data, function (&$key) { $key["transaction_date"] = date('d/m/Y',$key["transaction_date"]); } );

Answer 4

对多面额数组使用 array_walk_recursive 函数。

array_walk_recursive($data, function (&$v, $k) { 
    if($k == 'transaction_date'){ 
        $v = date('d/m/Y',$v); 
    } 
});