How to remove null from array in php

In php, we often need to operate on arrays, and sometimes we need to remove null values ​​​​in the array. If there is a null value in the array, it will affect our operation, so it needs to be removed from the array. This article will introduce several methods to remove null values ​​​​in arrays.

Method 1: Use the array_filter function

The array_filter function is a built-in function in PHP that can filter out values ​​in the array that do not meet the conditions of the callback function. We can determine whether the array element is null in the callback function, and return true if not, otherwise return false.

The following is a sample code that uses the array_filter function to remove null values ​​​​in an array:

$original_array = array('a' => 1, 'b' => null, 'c' => 3, 'd' => null);
$new_array = array_filter($original_array, function($value) {
    return !is_null($value);
});
print_r($new_array);

The output result is:

Array
(
    [a] => 1
    [c] => 3
)

Using the array_filter function can very conveniently filter out the null values ​​​​in the array The null value.

Method 2: Use foreach loop

We can also use foreach loop to traverse the array, and determine whether it is null during the traversal process. If not, add it to a new array middle.

The following is a sample code that uses a foreach loop to remove null values ​​​​in an array:

$original_array = array('a' => 1, 'b' => null, 'c' => 3, 'd' => null);
$new_array = array();
foreach ($original_array as $key => $value) {
    if (!is_null($value)) {
        $new_array[$key] = $value;
    }
}
print_r($new_array);

The output result is:

Array
(
    [a] => 1
    [c] => 3
)

Using a foreach loop can also easily filter out arrays null value in .

Method 3: Use the array_diff function

We can also use the array_diff function to take the difference between the null value in the array and an array containing only null values. The result is that it does not contain null. Array of values.

The following is a sample code that uses the array_diff function to remove null values ​​​​in an array:

$original_array = array('a' => 1, 'b' => null, 'c' => 3, 'd' => null);
$new_array = array_diff($original_array, array(null));
print_r($new_array);

The output result is:

Array
(
    [a] => 1
    [c] => 3
)

Using the array_diff function can also easily remove null values ​​​​in an array The null value.

Summary

The above are several common methods for removing null values ​​​​in arrays. Which method to use can be chosen according to the actual situation. If there are many null values ​​in the array, it is more convenient to use the array_filter function; if there are only a few null values ​​in the array, it is more appropriate to use the foreach loop or the array_diff function. However, it should be noted that when using these methods to remove null values, we need to pay attention to whether they will affect the keys or values ​​of the array to ensure that the results of our operations are correct.

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