How Can I Flatten a Nested Array in PHP?

Transforming Nested Array to a Single Dimension

In this programming scenario, you encounter an array consisting of single-element subarrays. The task at hand is to convert this multidimensional structure into a one-dimensional array.

PHP's Native Approach

PHP provides a convenient function called array_map that can handle this conversion efficiently. Here's an example:

$array = [[88868], [88867], [88869], [88870]];
$oneDimensionalArray = array_map('current', $array);

// Output: [88868, 88867, 88869, 88870]

The array_map function takes a callback function as its first argument and an array as its second argument. In this case, the callback function current retrieves the current element from each subarray, effectively flattening the array.

Generalization for Multi-Element Subarrays

If the subarrays contained multiple elements, the above approach would only return the first element of each subarray. To address this scenario, you can utilize the call_user_func_array function:

$oneDimensionalArray = call_user_func_array('array_merge', $array);

// Output: [88868, 88867, 88869, 88870]

The call_user_func_array function invokes a callback function with an array of arguments, in this case, the array of subarrays. The array_merge function combines all the elements into a single array, resulting in the desired conversion.

The above is the detailed content of How Can I Flatten a Nested Array in PHP?. For more information, please follow other related articles on the PHP Chinese website!