PHP中合併數組且key值不變

一般PHP中合併兩個數組都會使用array_merge()
例如：

$data1 = ['111' => 'aaa', '222' => 'bbb', '333' => 'ccc'];
$data2 = ['444' => 'ddd', '555' => 'eee', '666' => 'fff'];
$data = array_merge($data1, $data2);
var_dump($data);

得到結果：

array(6) {
  [0]=>
  string(3) "aaa"
  [1]=>
  string(3) "bbb"
  [2]=>
  string(3) "ccc"
  [3]=>
  string(3) "ddd"
  [4]=>
  string(3) "eee"
  [5]=>
  string(3) "fff"
}

可以看到使用array_merge()會重置key值，如果key值對我們有用，不想重置，可以使用"+"合併數組。

$data1 = ['111' => 'aaa', '222' => 'bbb', '333' => 'ccc'];
$data2 = ['444' => 'ddd', '555' => 'eee', '666' => 'fff'];
$data = $data1 + $data2;
var_dump($data);

得到結果：

array(6) {
  [111]=>
  string(3) "aaa"
  [222]=>
  string(3) "bbb"
  [333]=>
  string(3) "ccc"
  [444]=>
  string(3) "ddd"
  [555]=>
  string(3) "eee"
  [666]=>
  string(3) "fff"
}