When merging PHP arrays, how to merge different data types?

For merging arrays of different data types in PHP, there are three common methods: 1) array_merge_recursive, recursive merging, retaining sub-arrays; 2) PHP 7.4's spread operator, expanding the array; 3) Custom merge function, providing fine control .

PHP array merging between different data types

In PHP, when merging arrays, you often encounter different data types Data, in order to achieve the perfect merger of these data types, three common methods are introduced here, and practical cases are provided for demonstration.

1. array_merge_recursive

This function can recursively merge arrays and merge sub-arrays in the form of arrays without losing the data of the sub-arrays.

<?php
$array1 = ['a' => 1, 'b' => [3, 4], 'c' => ['d' => 6]];
$array2 = ['b' => [1, 2], 'e' => 5];

$mergedArray = array_merge_recursive($array1, $array2);

print_r($mergedArray); // 输出：
// Array
// (
//     [a] => 1
//     [b] => Array
//         (
//             [0] => 3
//             [1] => 4
//             [2] => 1
//             [3] => 2
//         )
//     [c] => Array
//         (
//             [d] => 6
//         )
//     [e] => 5
// )
?>

2. spread operator (PHP 7.4)

PHP 7.4 introduced the spread operator, which allows spreading an array within another array.

<?php
$array1 = ['a' => 1, 'b' => [3, 4]];
$array2 = ['b' => [1, 2], 'e' => 5];

$mergedArray = [...$array1, ...$array2];

print_r($mergedArray); // 输出：
// Array
// (
//     [0] => 1
//     [1] => 3
//     [2] => 4
//     [3] => 1
//     [4] => 2
//     [5] => 5
// )
?>

3. Custom merge function

If you need more fine-grained control over the merge process, you can write a custom merge function.

<?php
function custom_array_merge(array $array1, array $array2): array
{
    foreach ($array2 as $key => $value) {
        if (isset($array1[$key]) && is_array($array1[$key]) && is_array($value)) {
            $array1[$key] = custom_array_merge($array1[$key], $value);
        } else {
            $array1[$key] = $value;
        }
    }

    return $array1;
}

$array1 = ['a' => 1, 'b' => [3, 4], 'c' => ['d' => 6]];
$array2 = ['b' => [1, 2], 'e' => 5];

$mergedArray = custom_array_merge($array1, $array2);

print_r($mergedArray); // 输出：
// Array
// (
//     [a] => 1
//     [b] => Array
//         (
//             [0] => 3
//             [1] => 4
//             [2] => 1
//             [3] => 2
//         )
//     [c] => Array
//         (
//             [d] => 6
//         )
//     [e] => 5
// )
?>

The above is the detailed content of When merging PHP arrays, how to merge different data types?. For more information, please follow other related articles on the PHP Chinese website!