Why doesn't this function return the sum?

Question

function addit(x,y) {
var c = (x + y);
document.write("the sum is "+ c);
}

var x = prompt ("Type in first number");
var y = prompt ("Type in second number");
addit (x,y);

Answer 1

Because to return a value, the function must have a 'return' statement ^^

Answer 2

OK, I get it, thank you everyone for answering :-)

Answer 3

I guess javascript (as python) accepts standard input as string, not integer so you have to convert it, something like this. Srećno :)

function addit(x,y) {
var c = (Number(x) + Number(y));
return c;
}

var x = prompt ("Type in first number");
var y = prompt ("Type in second number");
var c = addit (x,y)
document.write("the sum is "+ c);