Add stuff with prompts

Question

I want to make a thing that adds two numbers with prompt()s and when it returns the sum it shows the numbers in the wrong way. For instance, I would put 5 for the first number and 2 for the second number and it returns 52. Here's the code

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Document</title>
</head>
<body>
    <h2 id="h2">gonna be something</h2>
    <button onclick="math()">might do something</button>
    <script>
        function math() {
        var text = document.getElementById("h2")
        var question1 = prompt("enter a number","here")
        var question2 = prompt("enter a second number","here")
        text.innerHTML = 
        question1 += question2
        }
    </script>
</body>
</html>

`text.innerHTML = question1 += question2` that is just strange syntax — epascarello, Mar 16 '21 at 19:15

fonini · Accepted Answer · 2021-03-16T19:17:16.697

You have to convert the prompt return to int in order to do the calculation. If you don't do it, the values will be concatenated instead of added.

var question1 = parseInt(prompt("enter a number","here"))
var question2 = parseInt(prompt("enter a second number","here"))

You can also test if the input was really a number before the conversion:

var question1 = prompt("enter a number","here")
var question2 = prompt("enter a second number","here")

if (!isNaN(question1) && !isNaN(question2)){
  question1 = parseInt(question1)
  question2 = parseInt(question2)
}

Add stuff with prompts

1 Answers1