如何更改基于另一个键的数组键的值？

Question

我有这个变量是我的查询结果：

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

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

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

现在我想改变[id]项目的数量时，其[visibility]是0。例如，我想在[id]的数字的开头追加00。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？

---

我可以检查visibility值是这样的：

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

Answer 1

你开始foreach和正确的条件检查，但没写里面的任何代码。检查下面： -

<?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

稍微容易引用$item并改变它：

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