<?php

// Original Arrays
$a = array(0,1,2,3,4,5);
$b = array(6,7,8,9,10);

// Create an empty new array
$ab = array();

// Add all the values from array a to the new array
foreach ($a as $value) {

    $ab[] = $value;

}

// Add all the values from array b to the new array
foreach ($b as $value) {

    $ab[] = $value;

}

// Sort the array in ASC order
sort($ab);

// Print the new array
echo '<pre>';
print_r($ab);
echo '</pre>';