How to find the sum of variables in javascript?

Question

var pagenumber = localStorage["pageno"];
var sum = pagenumber + i;
display(sum);

In this case i am getting the output sum = 11 (when input pagenumber = 1 and i = 1) , But i require the output sum = 2

Answer 1

Need to parse the "1" in localStorage to an integer using the built in parseInt funtion:

var pagenumber = localStorage["pageno"];
var sum = Number.parseInt(pagenumber) + i;
display(sum);

Answer 2

You can use parseInt to convert your strings to integers in JavaScript:

var sum = parseInt(localStorage["pageno"]) + parseInt(i);
display(sum);