PHP pushes elements to the head of the array (usage of array_unshift)_PHP tutorial

In PHP, the most common way to add elements to an array is the array_push function, which is the push operation of the array. However, this function adds elements to the end of the array. If you need to push the array elements into the array How to operate the head (i.e. the first element)?

Use PHP’s built-in function array_unshift. The usage of array_unshift function is listed below.

array_unshift

The function of this function is to insert one or more elements at the beginning of the array. The added elements are added as a whole, in the same order in the array as in the parameters. All numeric key names in the modified array will be modified to count again from zero, and all text key names will remain unchanged. This function returns the number of elements in the array after the operation.

Syntax: int array_unshift ( array &$array ,mixed $var [,mixed $... ] )

For example:

<?php
$queue = array("phpernote",".com");
array_unshift($queue,"apple","raspberry");
print_r($queue);

The above routine will output:

Array
(
[0] => apple
[1] => raspberry
[2] => phpernote
[3] => .com
)

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http://www.bkjia.com/PHPjc/764084.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/764084.htmlTechArticleIn PHP, the more common way to add elements to an array is the array_push function, which is the push operation of the array, but this The function is to add elements to the end of the array. If you need to compress the array elements...