How to merge and replace array elements in php

Implementation steps: 1. Use the array_merge() function to merge two, the syntax "array_merge(array 1, array 2....)" will return a merged array containing two array elements; 2. Use the array_splice() function to replace the elements in the merged array. The syntax "array_splice(merged array, starting position, number, replacement value)" can replace the specified number of elements starting from the specified position. If multiple values ​​are replaced, replace Values ​​can be arrays.

The operating environment of this tutorial: windows7 system, PHP8.1 version, DELL G3 computer

php merge and replace array elements can be divided into Two steps:

• Merge two arrays

• Replace the merged array

Implementation steps:

Step 1. Use the array_merge() function to merge two arrays

array_merge() function is used to merge one or more arrays into one array , will return a merged array containing two array elements

Note: If two or more array elements have the same key name, the last element will overwrite the other elements.

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$a1=array(1,2,3,4,5,0);
$a2=array(6,7,8,9,10);
var_dump($a1);
var_dump($a2);
$arr=array_merge($a1,$a2);
var_dump($arr);
?>

Step 2: Use array_splice() function to replace the merged array

array_splice() function to remove from the array Selected element and replace it with new element.

array_splice() function will change the original array

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$a1=array(1,2,3,4,5,0);
$a2=array(6,7,8,9,10);
$arr=array_merge($a1,$a2);
var_dump($arr);
echo "替换合并数组第4个元素";
array_splice($arr,3,1,"hello");
var_dump($arr);
?>

Description:

array_splice() function is used Deletes part of an element from an array; you can delete it directly or replace it with another value.

array_splice() syntax is as follows:

array array_splice ( array &$arr, int $start [, int $length = 0 [, mixed $replacement ]] )

Parameter description:

• arr represents an array.
• start indicates the position (subscript) where deletion begins:
  • If start is a positive number, delete from front to back.
  • If start is a negative number, start from the position -start from the end of arr and delete from back to front. For example -2 means start from the second to last element of the array.
• length is an optional parameter, indicating the number of elements to be deleted:
  • If length is a positive number, it means length elements are deleted;
  • If length is a negative number, all elements starting from start and counting down to length from the end of the array will be deleted;
  • If it is omitted, all elements starting from start and ending at the end of the array will be deleted.
• replacement is an optional parameter indicating the value to be replaced. If replacement has multiple values, it needs to be set to an array. If there is only one value, it does not need to be set to an array.

If the combination of start and length results in no element being deleted, then the value contained in replacement will be inserted into the position specified by start.

Note that using replacement to replace array elements will not retain the original key names.

Return value: Returns an array consisting of the deleted elements.

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to merge and replace array elements in php. For more information, please follow other related articles on the PHP Chinese website!