How to merge arrays in php without using functions

In PHP, we usually use the array_merge() function to merge two or more arrays. However, sometimes we need a more efficient way to merge arrays and need to avoid using function calls. In this article, we will share some ways to merge arrays without using functions.

1. Use Operator

Operator can be used to merge two arrays. It will merge the left array with the right array and remove the same key names in the right array as in the left array. Here is an example of merging arrays using the operator:

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

$result = $arr1 + $arr2;

print_r($result); // 输出：Array ( [a] => 1 [b] => 2 [c] => 4 )

In the above example, the key name in the $arr1 array is b The key names in the and $arr2 arrays are b. After merging the two arrays using the operator, only the $result remains in the array. b in $arr1, and b in $arr2 are ignored.

2. Use the $array[] syntax

In PHP, you can use the $array[] syntax to add elements to the end of the array. This way we can merge two arrays into one. Here is an example of merging arrays using the $array[] syntax:

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

foreach ($arr2 as $key => $value) {
    $arr1[$key] = $value;
}

print_r($arr1); // 输出：Array ( [a] => 1 [b] => 3 [c] => 4 )

In the above example, we iterate over the $arr2 array, merging each Elements are added to the $arr1 array. In this way, we can add the elements of the $arr2 array to the $arr1 array, thereby merging the arrays.

3. Alternative method of using array_replace_recursive() function

In PHP, we can use the array_replace_recursive() function to merge two arrays . However, this function recursively merges elements from two arrays, so it may be slower when working with large arrays. Here is an example of merging arrays using the array_replace_recursive() function:

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

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

print_r($result); // 输出：Array ( [a] => Array ( [b] => 2 [c] => 4 [d] => 5 ) )

In the above example, the a elements in the $arr1 array Contains the c elements in the $arr2 array. After merging the two arrays using the array_replace_recursive() function, the $result # in the array The ##a element contains the c and d elements in the $arr2 array.

However, there is a way to avoid using the

array_replace_recursive() function and achieve merging of arrays at the same time. We can use the array_merge_recursive() function and the array_replace() function. Here is an example of merging arrays using this method:

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

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

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

print_r($result); // 输出：Array ( [a] => Array ( [b] => 2 [c] => 4 [d] => 5 ) )

In the above example, we first merge the two arrays using the

array_merge_recursive() function and then use array_replace () The function overwrites the elements in the $arr1 array into the result array. In this way, we successfully merged the two arrays into one.

Summary:

In PHP, we usually use the

array_merge() function to merge two or more arrays. In this article, we introduced ways to merge arrays without using functions, including alternatives using the operator, $array[] syntax, array_merge_recursive() function wait. These methods can improve the efficiency of your code and reduce the overhead of function calls.

The above is the detailed content of How to merge arrays in php without using functions. For more information, please follow other related articles on the PHP Chinese website!