What are the other extension functions for PHP array merging?

PHP provides 3 extension functions for merging arrays: array_merge_recursive() recursively merges arrays, array_replace() overwrites values ​​with the same key name, and array_replace_recursive() recursively overwrites values ​​in arrays.

Other extension functions for PHP array merging

In addition to the array_merge() function, PHP also provides Other extension functions are used to merge arrays. These functions provide different merging options that can be used to handle more complex situations.

1. array_merge_recursive()

This function recursively merges two or more arrays. Unlike array_merge(), it does not overwrite existing key names, but merges their subarrays into the final result.

$arr1 = ['a' => 1, 'b' => ['c' => 3, 'd' => 4]];
$arr2 = ['a' => 2, 'b' => ['e' => 5, 'f' => 6]];

$result = array_merge_recursive($arr1, $arr2);

var_dump($result);

Output:

array(2) {
  ["a"]=>
  int(2)
  ["b"]=>
  array(3) {
    ["c"]=>
    int(3)
    ["d"]=>
    int(4)
    ["e"]=>
    int(5)
  }
}

2. array_replace()

This function replaces the same key name in the first array with the second array value. It does not merge the arrays, but overwrites the values ​​in the first array with the values ​​in the second array.

$arr1 = ['a' => 1, 'b' => 2, 'c' => 3];
$arr2 = ['b' => 4, 'd' => 5];

$result = array_replace($arr1, $arr2);

var_dump($result);

Output:

array(4) {
  ["a"]=>
  int(1)
  ["b"]=>
  int(4)
  ["c"]=>
  int(3)
  ["d"]=>
  int(5)
}

3. array_replace_recursive()

This function is similar to array_replace(), but it is recursive Replace values ​​in an array. This means that the values ​​in the subarray will also be replaced.

$arr1 = ['a' => 1, 'b' => ['c' => 3, 'd' => 4]];
$arr2 = ['b' => ['e' => 5, 'f' => 6]];

$result = array_replace_recursive($arr1, $arr2);

var_dump($result);

Output:

array(2) {
  ["a"]=>
  int(1)
  ["b"]=>
  array(2) {
    ["e"]=>
    int(5)
    ["f"]=>
    int(6)
  }
}

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