How to delete the head, tail, and any element in a PHP array

In a previous article, we introduced "How to add elements to the head and tail of a PHP array" Since there are elements to add, there are elements to delete. Today's article details how to delete them. The head and tail elements of an array, as well as any array elements.

Delete the last element: array_pop

Just like the bullet clip, the last bullet pressed in is the first to pop out. In the computer In terminology, we call it first-in-last-pop

Since array_push adds an element to the end of the array, array_pop deletes an element from the end of the array.

The array_pop() function gets and returns the last element of the array, and reduces the length of the entire array by 1. If the array is empty (or not an array), then null is returned.

The syntax format is as follows:

mixed array_pop ( array &$array )

The parameter array is the input array.

The following is an example of the array_pop() function deleting the last element of the group number. The specific code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$atr = array("PHP","JAVA","ASP","VB");    //定义数组
$array = array_pop($atr);                     //删除数组中最后一个元素
echo "被删除的元素是; $array<br>";          //输出被删除的元素
print_r($atr);                               //打印数组结构
?>

The output result is:

Delete the header element: array_shift

In addition to first-in-last-out, there is also a first-in-first-out stack in the computer, which can be regarded as a pipe, first in The elements come out first

Since array_pop can pop elements from the end of the array, there should be a function that can pop elements from the head of the array. We use array_shift

mixed array_shift ( array &$array )

Below we will use array_shift( ) function to realize the instance of deleting the head element in the array. The specific code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$atr = array("PHP","JAVA","ASP","VB");    //定义数组
$array = array_shift($atr);                     //删除数组中第一个元素
echo "被删除的元素是; $array<br>";          //输出被删除的元素
print_r($atr);                               //打印数组结构
?>

The output result is:

In fact The syntax for deleting head elements and deleting tail elements in a group is the same, but the functions used are different!

##Delete any element in the array

Above we introduced how to delete the head and tail elements of the array. Deleting any element in the array is simpler than the previous two. To delete any element, you can just use unset!

Below we will use the unset function to delete element instances in any array. The specific code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$atr = array("PHP","JAVA","ASP","VB");    //定义数组
unset($atr[1]); // 删除JAVA
print_r($atr);                               //打印数组结构
?>

The output result is:

Explanation: What is deleted above is the index array. The index array can be deleted according to the specified subscript. If the element is deleted from the associated array, the specified element can be deleted according to the key!

The following example is how to

delete elements in an associative array, the specific code is as follows;

<?php
header("Content-Type:text/html; charset=utf-8");
$atr = array("name"=>"PHP中文网","URL"=>"www.php.cn","QQ"=>"88526");    //定义数组
unset($atr["QQ"]);                      // 删除88526
print_r($atr);                               //打印数组结构
?>

The output result is:

Instructions

unset can delete any variable or array

The reference code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
$atr = array("name"=>"PHP中文网","URL"=>"www.php.cn","QQ"=>"88526");    //定义数组
unset($atr); // 删除数组
var_dump($atr);                              //打印数组结构
?>

The output result is:

In the next article we will introduce "

How to delete duplicate elements in PHP arrays"!

【Related tutorial recommendations】

1. Relevant topic recommendations: "

php array (Array) 》

2. Recommended related video courses: "

Use arrays to implement stack operations: array_push and array_pop》

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