merge 2 array (not sorted)

mergearray.php

<?php
    $max = 10; 
    $arr = range(1,$max,3); 
    $arr2 = range(1,$max,2); 
    $arr = array_merge($arr,$arr2); 
    $res2 = array(); 
    foreach($arr as $key=>$val) {    
        $res2[$val] = true; 
    } 
    $res2 = array_keys($res2); 
	echo "<br>";
	echo json_encode($res2);
    
?>