How to remove values ​​from php array (three methods)

PHP is a powerful programming language that provides a wealth of array processing functions, allowing us to easily perform various operations on arrays. In actual development, we often need to deduplicate arrays or delete certain values. So, how to use PHP to deduplicate or delete values ​​in an array? This article will introduce you in detail to several methods of removing values ​​from PHP arrays.

Method 1: array_unique()

The array_unique() function can remove duplicate values ​​from the array and return a new array. This function is very simple and easy to use. You only need to pass it the array that needs to be deduplicated.

Sample code:

<?php
$arr = array(1,2,2,3,4,4,5);
$new_arr = array_unique($arr);
print_r($new_arr);
?>

Running result:

Array
(
    [0] => 1
    [1] => 2
    [3] => 3
    [4] => 4
    [6] => 5
)

It can be seen that the array_unique() function has successfully removed duplicate values ​​​​in the original array.

Method 2: array_diff()

The array_diff() function can be used to compare the difference between two or more arrays and return a new array that contains the first array values ​​that are not contained in other arrays.

We can use the array_diff() function to delete specific values ​​in the array. For example, if you need to delete the element equal to 3 in the array, you can implement it with the following code:

<?php
$arr = array(1,2,3,4,5);
$new_arr = array_diff($arr, array(3));
print_r($new_arr);
?>

Running results:

Array
(
    [0] => 1
    [1] => 2
    [3] => 4
    [4] => 5
)

You can see that the array_diff() function has successfully removed the element equal to 3 in the array. deleted.

Method Three: Loop Traversal to Delete Elements

In addition to the above two methods, we can also use loop traversal to delete specific values ​​in the array. This method requires no additional functions, but does require a bit more code.

Sample code:

<?php
$arr = array(1,2,3,4,5);
for($i = 0; $i < count($arr); $i++){
    if($arr[$i] == 3){
        array_splice($arr, $i, 1);
        $i--;
    }
}
print_r($arr);
?>

Running result:

Array
(
    [0] => 1
    [1] => 2
    [2] => 4
    [3] => 5
)

It can be seen that the deletion of specific values ​​in the array can also be achieved by using loop traversal.

To sum up, PHP provides a variety of methods to deduplicate or delete values ​​in an array. We can choose the appropriate method for processing according to actual needs. Of course, there are other functions or techniques that can achieve similar functions. I hope readers will explore more of their own methods while studying.

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