可能重复：
比较多维数组中的元素
我的阵列看起来像
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是重复的，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
)
)
像这样的东西会起作用：
$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是源数组。