如果值重复，则从多维数组中删除

Question

  

可能重复：
  Comparing elements in a multidimensional array

我的数组看起来像

Array
(
    [0] => Array
        (
            [event_key] => 1
            [event_id] => 5
            [event_desc] => Test Event 1
        )

    [1] => Array
        (
            [event_key] => 2
            [event_id] => 2
            [event_desc] => Test Event 2
        )

    [2] => Array
        (
            [event_key] => 3
            [event_id] => 5
            [event_desc] => Test Event 3
        )

    [3] => Array
        (
            [event_key] => 4
            [event_id] => 4
            [event_desc] => Test Event 4

        )

    [4] => Array
        (
            [event_key] => 5
            [event_id] => 5
            [event_desc] => Test Event 5

        )

)

如果event_id重复，我想删除一个子数组

所以期望的结果是

Array
(
    [0] => Array
        (
            [event_key] => 1
            [event_id] => 5
            [event_desc] => Test Event 1
        )

    [1] => Array
        (
            [event_key] => 2
            [event_id] => 2
            [event_desc] => Test Event 2
        )

    [2] => Array
        (
            [event_key] => 4
            [event_id] => 4
            [event_desc] => Test Event 4

        )


)

Answer 1

这样的事情可以解决问题：

$knownIds = array();
foreach( $myArray AS $key=>$item ) {
  if( array_key_exists($item['event_id'], $knownIds) === true ) {
    unset( $myArray[$key] );
  } else {
    $knownIds[$item['event_id']] = $key;  // value does not matter really here
  }
}
$myArray = array_values($myArray);

其中$myArray是您的源数组。