How to determine whether array a completely belongs to array b in php

Judgment steps: 1. Use "array_intersect_assoc(array b, array a)" to compare the key names and key values ​​of array a and array b, and return an intersection array containing the same elements; 2. Use "array_diff_assoc( Intersection array, array a)" compares the key names and key values ​​of array a and the intersection array, and returns a difference array containing different elements; 3. Use "$diff==[]" to determine whether the difference array is empty. If If it is empty, array a completely belongs to array b, otherwise it does not belong completely.

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

php determines array a Whether it completely belongs to array b

In PHP, you can use the array_intersect_assoc() and array_diff_assoc() functions to detect whether array a completely belongs to array b.

Step 1: Use the array_intersect_assoc() function to compare array a and array b and obtain the intersection

array_intersect_assoc() function will compare the key names and keys of array a and array b value, and returns an intersection array containing the same elements

<?php
header("Content-type:text/html;charset=utf-8");
$arr1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");;
$arr2=array("a"=>"red","b"=>"green","c"=>"blue");
var_dump($arr1);
var_dump($arr2);
echo "交集数组：";
$intersect=array_intersect_assoc($arr1,$arr2);
var_dump($intersect);
?>

Step 2:Use the array_diff_assoc() function to compare array a and intersection array, take the difference set

array_diff_assoc() function will compare the key names and key values ​​​​of array a and the intersection array, and return a difference array containing different elements

echo "差集数组：";
$result=array_diff_assoc($intersect,$arr2);
var_dump($result);

Step 3: Use the "==" operator to determine whether the difference array is empty

$diff==[]

• If it is empty, then Array a completely belongs to array b

• If it is not empty, array a does not completely belong to array b

##Full example code:

<?php
header("Content-type:text/html;charset=utf-8");
$arr1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$arr2=array("a"=>"red","b"=>"green","c"=>"blue");
var_dump($arr1);
var_dump($arr2);
echo "交集数组：";
$intersect=array_intersect_assoc($arr1,$arr2);
var_dump($intersect);
echo "差集数组：";
$diff=array_diff_assoc($intersect,$arr2);
var_dump($diff);
if($diff==[]){
	echo &#39;$arr2完全属于$arr1&#39;;
}else{
	echo &#39;$arr2不完全属于$arr1&#39;;
}
?>

Recommended learning: "

PHP Video Tutorial"

The above is the detailed content of How to determine whether array a completely belongs to array b in php. For more information, please follow other related articles on the PHP Chinese website!