[manoch]

to kthilagarajan
The same problem i think because options JSON_NUMERIC_CHECK has not work for MyComnputer /localhost or appserv
you can test code http://phptester.net/ with example code

<?php
$stack = array("100",  "200");
array_push($stack, "300", "400");
//print_r($stack);

echo json_encode($stack,JSON_NUMERIC_CHECK);//this line for my computer is error
echo json_encode($stack,128);//same echo json_encode($stack); 

you will see different output.
sory for english word .

Good luck.
Manoch