Adding problem, i want 2+2=4, but its giving 2+2=22; how to correct it.

Question

function add()
{
var fnum=document.getElementById("fnum").value;
var snum=document.getElementById("snum").value;
var res=fnum+snum;

document.write(res);
}
this is my code to add to numbers, but its simply joining 2 numbers,
like+
2+2=22;
I am not getting why its so.

Answer 1

Use parseInt(string)

hope this helps

Here is an example

https://code.sololearn.com/WW0fFXBzPIpz/?ref=app

Answer 2

Try:
var res=+fnum + +snum;
instead of
var res=fnum + snum;

Answer 3

OK,

Answer 4

but can u please little explain logic for doing this...

Answer 5

Yeah, the + symbol evaluates the string as a number. You're adding up two strings now, so setting them both to a number value will make them add up.
See http://xkr.us/articles/javascript/unary-add/ for a detailed explanation

Answer 6

thanx mart

Answer 7

Number() class makes sure if the value is a Number or not
So modify your script like this.

function add()
{
var fnum=Number(document.getElementById("fnum").value);
var snum=Number(document.getElementById("snum").value);
var res=Number(fnum+snum);

document.write(res);
}
I hope it works

Answer 8

thanx to all of you, if possible I want to discuss more, on creating a calculator,

my problem in creating calculator-

1. TO GET AS MANY VALUES AS POSSIBLE.
2.TO MAKE A FUNCTION WHICH CLEAR VALUE.
3. TO MANAGE VARIOUS OPERATORS GIVEN BY USER
4. TO SHOW DISPLAY LIMIT ERROR AND SYNTAX ERROR.

I AM GOOGLING OUT ABOUT THIS,
BUT LITTLE LITTLE HELP AND HINTS CAN FILL UP MY OCEAN.