How to merge arrays in php without changing the key

Method: 1. Use the " " operator, the syntax is "array 1 array 2"; 2. Use the array_merge_recursive() function. When two or more array elements have the same key name, no Instead of key name overwriting, multiple values ​​with the same key name are recursively formed into an array.

The operating environment of this tutorial: Windows 7 system, PHP version 7.1, DELL G3 computer

Generally, array_merge is used to merge two arrays in PHP ()

For example:

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

Get the result:

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"
}

You can see that using array_merge() will reset the key value. If the key value is useful to us, we don’t want to reset it. , you canuse " "to merge arrays.

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

Get the result:

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"
}

You can alsoUse the array_merge_recursive function to merge the cells of one or more arrays, and the values ​​in one array are appended to the previous one behind the array. Returns the resulting array.

This function is an upgraded version of array_merge. It adds the following functions on the basis of array_merge: If the key value is the same, it is the same as array_merge when it is a number, and re-indexed; if it is a string, it will no longer overwrite the previous one. Instead, it is appended to the back in a recursive manner; for example:

 /* array_merge_recursive */
$jiaArr = array(
	'name1'=>'xiaoli',
	'name2'=>'xiaohua',
	'name3'=>'xiaoming',
	'1'=>'teacher',
);
 
$jiaBrr = array(
	'name1'=>'xiaolis',
	'name5'=>'xiaohuas',
	'name6'=>'xiaomings',
	'1'=>'teachers',
);
$jiaAll = array_merge_recursive($jiaArr,$jiaBrr);
var_dump($jiaAll);
 
/*浏览器output：
array(7) {
  ["name1"]=>
  array(2) {
    [0]=>
    string(6) "xiaoli"
    [1]=>
    string(7) "xiaolis"
  }
  ["name2"]=>
  string(7) "xiaohua"
  ["name3"]=>
  string(8) "xiaoming"
  [0]=>
  string(7) "teacher"
  ["name5"]=>
  string(8) "xiaohuas"
  ["name6"]=>
  string(9) "xiaomings"
  [1]=>
  string(8) "teachers"
}
*/

name1 is present in both arrays, but is not overwritten but appended recursively, and the 1 array key values ​​are still reordered;

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