How to determine whether two arrays intersect in PHP

Judgment steps: 1. Use the array_intersect_assoc() function to compare the key names and key values ​​of the two arrays. The syntax "array_intersect_assoc (array 1, array 2)" will return an intersection array; 2. Use "== The =” operator determines whether the intersection array is empty. The syntax is “intersection array ===[]”. If the intersection array is empty, the two arrays have no intersection. If the intersection array is not empty, the two arrays have intersection.

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

In php, you can use the array_intersect_assoc() function and "===" operator to determine whether the two arrays have intersection.

Implementation steps:

Step 1: Use the array_intersect_assoc() function to compare arrays and find the intersection of the two arrays

array_intersect_assoc The () function is used to compare the key names and key values ​​of two (or more) arrays and return an array containing the intersection elements (an intersection array).

$result=array_intersect_assoc($a1,$a2);

Step 2: Use the "===" operator to determine whether the intersection array is empty

$result===[]

If the intersection array is empty, the two arrays have no intersection. If the intersection If the array is not empty, the two arrays have intersection.

Complete sample code:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
function f($a1,$a2){
	$result=array_intersect_assoc($a1,$a2);
	var_dump($result);
	if($result===[]){
		echo &#39;两数组没有交集&#39;;
	}else{
		echo &#39;两数组有交集&#39;;
	}
}


$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("a"=>"red","b"=>"green","c"=>"blue");
$a3=array("a"=>"1","b"=>"2","d"=>"blue");
var_dump($a1);
var_dump($a2);
echo &#39;$a1 和 $a2对比：&#39;;
f($a1,$a2);
echo &#39;<hr>&#39;;

var_dump($a2);
var_dump($a3);
echo &#39;$a2 和 $a3对比：&#39;;
f($a2,$a3);
?>

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