Question

我有这个变量，这是我查询的结果：

Array(
       [0] => Array
         (
             [id] => 1
             [visibility] => 0
         )

       [2] => Array
         (
             [id] => 2
             [visibility] => 1
         )

       [3] => Array
         (
             [id] => 3
             [visibility] => 0
         )
)

现在，我希望在[id]为[visibility]时更改0项的数量。例如，我想在00的数字的开头附加[id]。这是预期的输出：

Array(
       [0] => Array
         (
             [id] => 001
             [visibility] => 0
         )

       [2] => Array
         (
             [id] => 2
             [visibility] => 1
         )

       [3] => Array
         (
             [id] => 003
             [visibility] => 0
         )
)

我该怎么做？

我可以像这样检查visibility的值：

foreach ($var as $item) {
    if ($item['visibility'] == 0) {
        // I need to append two zero before the number of its id
    }
}

Answer 1

您启动了foreach并更正了条件检查，但未在其中写入任何代码。检查以下内容： -

   <?php
    foreach ($var as $key=> $item) {
        if ($item['visibility'] == 0) { // if visibility is 0
            $var[$key]['id'] = "00". $var[$key]['id']; // add 00 to corresponding id in the original array
        }
    }
    echo "<pre/>";print_r($var);
    ?>

Answer 2

稍微更容易引用$item并更改它：

foreach ($var as &$item) {
    if ($item['visibility'] == 0) {
        $item['id'] = "00{$item['id']}";
    }
}

如何在另一个键上更改数组的键值？

2 个答案: