I want to print sum of two numbers in Javascript

Question

My code is not working and I don`t know why. I want to make simple thing that input two numbers and prints the sum of them. This is my code:

<script type="text/javascript">
    var num1, num2, sum;
    num1 = window.prompt("Enter number one");
    num2 = window.prompt("Enter number two");
    sum = num1 + num2;
    window.alert(num1 + "+" + num2 + "=" + sum);
</script>

score 1 · Answer 1 · answered Nov 30 '14 at 11:33

1

<html>
    <head>
        <meta charset="UTF-8">
        <title>Page91Ex6</title>
    </head>
    <body>
        <script type="text/javascript">
            var num1, num2, sum;
            num1 = window.prompt("Enter number one");
            num2 = window.prompt("Enter number two");
            sum = parseInt(num1) + parseInt(num2);
            window.alert(num1 + "+" + num2 + "=" + sum);
        </script>
    </body>
</html>

answered Nov 30 '14 at 11:33

jay.jivani

1,560
1
16
33

1

Why do I need to do that? And thank you very much!! – user3819756 Nov 30 '14 at 11:34
1

because `+` in javascript consider as concatination operator so we have to parse integer value & then do sum – jay.jivani Nov 30 '14 at 11:35
1

@user3819756 asks a very good question, and that is the reason **code-only answers are disapproved of**. Please edit your answer and insert the explanation. – Jongware Nov 30 '14 at 11:37
You should use `parseInt(num, 10)` always. Never forget the base. – Aadit M Shah Nov 30 '14 at 12:14

I want to print sum of two numbers in Javascript

1 Answers1