Remove empty values ​​from php array

When developing web applications, it is often necessary to use arrays in PHP to store and process data. However, sometimes there may be some empty values ​​in the array, which will occupy a lot of memory and increase the complexity of the code. Therefore, knowing how to remove null values ​​from PHP arrays is a very important skill.

In PHP, we usually use the following two methods to remove null values ​​​​in the array:

1. Use the array_filter() function

In PHP The array_filter() function can be used to remove null values ​​from an array. Usage of this function is very simple, just pass the array as a parameter to the function. For example, we can use the following code to remove null values ​​​​in the array $data:

$data = array("apple", "", "orange", null, "banana", false, 0, "grape");
$data = array_filter($data);
print_r($data);

Run the above code, the output result is:

Array
(
    [0] => apple
    [2] => orange
    [4] => banana
    [7] => grape
)

As shown above, the array_filter() function has The null values ​​are removed and a new array is returned.

2. Use foreach loop to traverse the array

In addition to using the array_filter() function, we can also use the foreach loop to traverse the array and add non-null values ​​to a new in the array. For example, the following code demonstrates how to use a foreach loop to remove null values ​​​​in an array:

$data = array("apple", "", "orange", null, "banana", false, 0, "grape");
$new_data = array();
foreach ($data as $value) {
  if (!empty($value)) {
    $new_data[] = $value;
  }
}
print_r($new_data);

Run the above code, the output is:

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

As shown above, we use a foreach loop to loop through the original array and check if each value is empty. If the value is not empty, add it to a new array. Finally, we get a new array with no null values.

Summary

Removing null values ​​​​from an array is very simple in PHP. We can use the array_filter() function or foreach loop to achieve it. In actual development, which method to use depends on your personal preferences and performance needs. No matter which method is used, removing null values ​​​​from an array is a very basic skill that every PHP developer should master.

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