php removes array as empty

In PHP development, scenes that often involve operating arrays are involved. However, sometimes we encounter some null values ​​in the array, and these null values ​​will affect our processing of data. Therefore, we need to remove the null values ​​in these arrays. In this article, we will introduce how to use PHP to remove null values ​​​​from an array.

1. Use the array_filter function

The array_filter function is a built-in function in PHP, which can filter the data in the array and retain the required data. When operating an array, we can use the array_filter function to filter null values ​​in the array. The following is a sample code:

$arr = array("", "apple", "banana", "", "pear");
$result = array_filter($arr);
print_r($result);

The result of running the code is as follows:

Array
(
    [1] => apple
    [2] => banana
    [4] => pear
)

You can see that after using the array_filter function, the null values ​​​​in the array have been removed.

2. Using foreach loop

In addition to using the array_filter function, we can also use foreach loop to remove null values ​​​​in the array. The specific implementation is as follows:

$arr = array("", "apple", "banana", "", "pear");
$result = array();
foreach($arr as $value) {
    if(!empty($value)) {
        $result[] = $value;
    }
}
print_r($result);

The code running result is as follows:

Array
(
    [0] => apple
    [1] => banana
    [2] => pear
)

In this example code, we first define an empty array $result, and then traverse each element in the original array $arr through a foreach loop elements, if the current element is not empty, add it to the $result array.

3. Use the array_map function

In addition to the above two methods, we can also use the array_map function to remove null values ​​​​in the array. The array_map function can execute a callback function for each element in the array, and the return value of the callback function is the processed new element value. The following is a sample code:

$arr = array("", "apple", "banana", "", "pear");
$result = array_map("trim", $arr);
$result = array_filter($result);
print_r($result);

The code running results are as follows:

Array
(
    [1] => apple
    [2] => banana
    [4] => pear
)

In this sample code, we use two functions: array_map and array_filter. First, we use the array_map function to perform the trim function on each element in the array to remove spaces. Then, we use the array_filter function to remove null values ​​in the array.

Summary

Removing null values ​​​​in an array is a problem often encountered in PHP. We can easily implement this function by using methods such as array_filter, foreach loop, and array_map. In actual development, we should choose an appropriate method to handle null values ​​in the array according to the actual situation to achieve the optimal effect.

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