array_diff没有按预期工作？ 可能是什么原因？

Question

I have two arrays .
Check the code

$array1 = array(0=>'215',1=> '225');
$array2 = array(0=>'225');
$diff_result = array_diff($array1, $array2);
$diff = array_values($diff_result);
print_r($array1);echo "<br>";
print_r($array2);echo "<br>";
print_r($diff_result);echo "<br>";
print_r($diff);

Now I am getting answers as

Array ( [0] => 215 [1] => 225 )
Array ( [0] => 225 )
Array ( [0] => 215 [1] => 225 )
Array ( [0] => 215 [1] => 225 ) 

But according to array_diff manual it should be

Array ( [0] => 215 [1] => 225 ) 
Array ( [0] => 225 ) 
Array ( [0] => 215 ) 
Array ( [0] => 215 )

What could be the problem

Answer 1

It was not working for me (dont know why) so I changed the code to calculate difference in two array

for ($i = 0; $i < count($array2); $i++) { 
    for ($j = 0; $j < count($array1); $j++) {
        if(!in_array($array1[$j],$array2)){ 
            $resArr[] = $array1[$j]; 
        } 
    } 
}
print_r($array1);echo "<br>";
print_r($array2);echo "<br>";
print_r($resArr);echo "<br>";

Thanks for the time