Unexpected output in javascript

Question

I am beginner to javascript and i am getting unexpected output

here is the code

Answer 1

This is because the prompt function returns a String and not a Number. So what you're actually doing is to request 2 strings and then concatenate them. If you want to add the two numbers together you'll have to convert the strings to numbers:

var num1 = parseFloat(prompt("what is your no."));
var num2 = parseFloat(prompt("what is another no."));

or simpler:

var num1 = +prompt("what is your no.");
var num2 = +prompt("what is another no.");