How to intercept the first few elements after merging arrays in php

Implementation method: 1. Use array_merge() to merge one or more arrays into one array, the syntax is "array_merge(array 1, array 2...)"; 2. Use array_slice() to intercept the first N array elements, the syntax is "array_slice(merged array,0,N)".

The operating environment of this tutorial: Windows 7 system, PHP version 8.1, DELL G3 computer

After php merges the arrays Methods to intercept the first few elements

1. Use array_merge() to merge arrays

array_merge() function is used to merge one or more Arrays are combined into one array.

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);
$arr=array_merge($a1,$a2);
var_dump($arr);
?>

2. Use the array_slice() function to intercept array elements

array_slice() function is provided by PHP to intercept arrays A function that extracts a fragment from an array. The syntax is as follows:

array array_slice ( array $arr , int $start [, int $length = NULL [, bool $preserve_keys = false ]] )

Parameter description:

• arr represents the array to be intercepted.
• start indicates the starting position (subscript) of interception:
  • If start is a positive number, interception will be performed from front to back.
  • If start is a negative number, start from the position -start from the end of arr and intercept 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 intercepted length:
  • If length is a positive number, it indicates the number of intercepted elements;
  • If length If it is a negative number, then the intercepted fragment will end at the length position from the end of the array;
  • If it is omitted, it will start from the start position and continue to the end of the array.
• preserve_keys is an optional parameter that specifies whether to retain the original key name. The default is false, that is, not retained; if set to true, the original key name will be retained.

<?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,$a2);
echo "合并后的数组：";
var_dump($arr);

echo "截取数组前2位的元素片段：";
$result = array_slice($arr,0,2); //截取数组前2位的元素
var_dump($result);

echo "截取数组前5位的元素片段：";
$result = array_slice($arr,0,5); //截取数组前5位的元素
var_dump($result);
?>

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