Remove empty elements from php array

When developing with PHP, you often need to operate on arrays. During this process, we may encounter empty array elements, which may prevent our code from running normally or cause confusion in the code logic. Therefore, removing empty elements from PHP arrays is one of the problems we need to deal with frequently. This article will introduce several methods to remove empty elements from PHP arrays.

1. Use the array_filter function

We can use the PHP built-in function array_filter to filter out empty elements in the array. This function returns a new array containing only non-empty elements in the original array.

The following is an example code for using the array_filter function to remove empty elements in an array:

$arr = array("apple", "banana", "", "orange", null);
$arr = array_filter($arr);
print_r($arr);

The output result is:

Array
(
    [0] => apple
    [1] => banana
    [3] => orange
)

It can be seen that this method can filter out the empty elements in the array Empty elements (including empty strings and null values) and returns a new array containing all non-empty elements.

2. Use foreach loop

We can also use foreach loop to traverse the array and store non-empty elements into a new array.

The following is an example code for using a foreach loop to remove empty elements in an array:

$arr = array("apple", "banana", "", "orange", null);
$newArr = array();
foreach ($arr as $val) {
    if (!empty($val)) {
        $newArr[] = $val;
    }
}
print_r($newArr);

The output result is:

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

As you can see, this method can also filter out arrays empty elements in and returns a new array containing all non-empty elements.

3. Use the array_map function

In some cases, we can use the array_map function to remove empty elements in the array. This function accepts a callback function as a parameter, applies the function to each element in the array, and returns the resulting array.

The following is a sample code that uses the array_map function to remove empty elements in an array:

$arr = array("apple", "banana", "", "orange", null);
$newArr = array_map('trim', $arr);
$newArr = array_filter($newArr);
print_r($newArr);

The output result is:

Array
(
    [0] => apple
    [1] => banana
    [3] => orange
)

As you can see, this method is removed by applying the trim function Remove the spaces in the array elements, then use the array_filter function to filter out the empty elements, and return a new array containing all non-empty elements.

4. Use the array_reduce function

The array_reduce function can perform reduction operations (also called folding) on ​​all elements in the array and return the final result.

The following is a sample code that uses the array_reduce function to remove empty elements in an array:

$arr = array("apple", "banana", "", "orange", null);
$newArr = array_reduce($arr, function ($carry, $item) {
    if (!empty($item)) {
        $carry[] = $item;
    }
    return $carry;
}, array());
print_r($newArr);

The output result is:

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

As you can see, this method uses the array_reduce function to Performs a reduction operation, stores non-empty elements into a new array, and returns the new array.

Summary:

Removing empty elements from PHP arrays is a common need. In this article, we introduce a variety of methods to solve this problem. Whether you use the array_filter function, the foreach loop, the array_map function, or the array_reduce function, each method has its use cases, pros and cons. Developers can choose the method that best suits them based on their specific needs.

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