Cannot retrieve integer value correctly with php

<?php
 
$cache = new Couchbase("10.80.10.247:8091", "root", "pass", "dev");
$cache->set('a', array());     //save an array first, even its length equals zero.
$cache->get('a');                 //retrieve the array.
 
$cache->set('b', 10);           //save an integer greater than 9.
var_dump($cache->get('b')); //the result is: int(100).