Remove all `null` values from an array in PHP

A convenient method to remove all null values from an array in PHP is by using the array_filter() function. As the name suggests the method filters a given array, if you don't supply your own filter function PHP filters out all values that evaluate as false in a condition; empty strings, 0, false, null.

To explicitly only filter out the null values you should pass your own callback function to the array_filter() function that only returns false if a given value is equal to null.

Using an arrow function that would look like the following:

<?php

$values = ['a', 'b', null, 'c'];

$result = array_filter($values, fn ($value) => !is_null($value));

print_r($result);
// Array
// (
//     [0] => a
//     [1] => b
//     [2] => c
// )

As I mentioned above, if you don't supply a callback function yourself PHP filters out all values that evaluate as false. So that includes other values besides null as well. But maybe that's just what you need. In that case, see the example below:

<?php

$values = ['a', '', null, false, []];

$result = array_filter($values);

print_r($result);
// Array
// (
//     [0] => a
// )