How to compare two arrays in php to see if they are different

Comparison method: 1. Use "array_diff(array 1, array 2)" to compare only array values; 2. Use "array_diff_assoc(array 1, array 2)" to compare both keys and values. After comparing the arrays, these two methods return a difference array; if the difference array is an empty array, the two arrays are the same, and vice versa.

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

php comparison 2 Whether the arrays are different (not the same)

In PHP, you can use the array_diff() or array_diff_assoc() function to compare two arrays to see if the two arrays are different.

The array_diff() or array_diff_assoc() function will return a difference array after comparing arrays; if the difference array is an empty array, the two arrays are the same, and vice versa.

Let’s take a closer look:

Method 1: Use array_diff() to compare whether two arrays are different

array_diff() function is used Compares the values ​​of two arrays and returns the difference. Syntax format:

array_diff(array1,array2);

Return value:

• Returns a difference array that includes everything in the compared array (array1), but not in any other Values ​​in parameter arrays (array2, etc.).

Example:

<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"black","g"=>"purple");
$a3=array("a"=>"red","b"=>"black","h"=>"purple");

$result=array_diff($a1,$a2);
var_dump($result);

$result=array_diff($a2,$a3);
var_dump($result);
?>

Method 2: Use array_diff_assoc() function

The array_diff_assoc() function is used to compare the key names and key values ​​of two (or more) arrays and return the difference. Syntax format:

array_diff_assoc(array1,array2);

This function compares the key names and key values ​​​​of two (or more) arrays, and returns a difference array, which includes all the arrays being compared (array1), But the key name and key value are not in any other parameter array (array2).

Example:

<?php
$a1=array("a"=>"red","b"=>"black","g"=>"purple");
$a2=array("e"=>"red","f"=>"black","g"=>"purple");
$a3=array("a"=>"red","b"=>"blue","h"=>"yellow");
$a4=array("e"=>"red","f"=>"black","g"=>"purple");

$result=array_diff_assoc($a1,$a2);
var_dump($result);

$result=array_diff_assoc($a2,$a3);
var_dump($result);

$result=array_diff_assoc($a2,$a4);
var_dump($result);
?>

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