How to remove specified value from php array

In PHP, the skill of handling arrays is crucial. Often we need to operate on arrays to meet different needs. In this article, we will focus on how to remove values ​​from PHP arrays to meet our daily development needs.

PHP array is an unordered data structure that can accommodate various types of elements, such as strings, numbers, objects, etc. Using arrays allows us to easily manage and operate data. Let's look at several different methods of array removal.

1. Use unset to remove

In PHP, we can use the unset keyword to remove the specified value in the array. The unset syntax is as follows:

unset($arr["index"]);

Among them, $arr is the target array, and index is the subscript of the target element. The following is a sample code:

$fruits = array("apple", "banana", "orange", "pear");
unset($fruits[1]);
print_r($fruits);

The output is {"apple", "orange", "pear"}. You can see that banana has been successfully removed.

2. Use array_diff_key to remove

Sometimes we need to compare two arrays and then take out different elements. In this case, we can use the array_diff_key() function to achieve this.

This function compares the keys of two arrays and returns an array with different keys. The following is a sample code:

$array1 = array('a'=>1, 'b'=>2, 'c'=>3);
$array2 = array('b'=>2, 'd'=>4);
$result = array_diff_key($array1, $array2);
print_r($result);

The output is {"a"=>1, "c"=>3}. You can see that b has been successfully removed.

3. Use array_splice to remove

The array_splice() function is a built-in function in PHP. It can be used to remove elements from an array and insert new elements into the array. Specify location. This function returns an array of removed elements.

The sample code is as follows:

$array = array("apple", "pear", "banana", "orange");
array_splice($array, 2, 1); // 移除banana
print_r($array);

The output is {"apple", "pear", "orange"}, you can see that banana has been successfully removed.

4. Use array_filter to remove

The array_filter() function can filter the array and return a new array that only contains elements that meet the conditions.

This function accepts two parameters: target array and callback function. The callback function needs to return a Boolean value to indicate whether the element should be included.

The sample code is as follows:

$array = array("apple", "pear", "banana", "orange");
$new_array = array_filter($array, function($value) {
    return $value != "banana";
});
print_r($new_array);

The output is {"apple", "pear", "orange"}, you can see that banana has been successfully removed.

5. Use array_values ​​to remove

The last method is to use the array_values() function. This function returns a new array containing the values ​​of all elements in the target array, indexed numerically.

The sample code is as follows:

$array = array("apple", "pear", "banana", "orange");
$new_array = array_values($array);
unset($new_array[2]); // 移除banana
print_r($new_array);

The output is {"apple", "pear", "orange"}, you can see that banana has been successfully removed.

Summary

For removing values ​​from PHP arrays, we can use a variety of methods. We can use the unset() function to directly delete the target value, or use array_diff_key() to compare the keys of two arrays. We can also use array_splice() to remove elements at the target position, or we can use array_filter() to filter the elements we want to keep and Returns a new array. Finally, we can use the array_values() function to remove the specified values ​​and return a new array.

The above methods are not absolute. In fact, the implementation dimensions are very wide. Depending on the specific needs and scenarios, we can flexibly choose and apply these methods to meet our needs.

The above is the detailed content of How to remove specified value from php array. For more information, please follow other related articles on the PHP Chinese website!