HTML input field datatype issue

Question

I have an issue with input fields. I have 2 input field type="number" and I would just like to add those 2 number together. My input fields

<input type="number" name="a" id="a" onchange="add()">
<input type="number" name="b" id="b" onchange="add()">

This is my js file

function add() {
var a = document.getElementById("a").value;
var b = document.getElementById("b").value;
var c = a + b;
}

Issue is when I try 20+20 result is 2020, not 40 as I would expect.

Input values are strings. Even if the type is number. – Taplar Aug 13 '20 at 14:03 — Taplar, Aug 13 '20 at 14:03

cagcoach · Accepted Answer · 2020-08-14T09:26:21.420

1

You can use the parseInt() function to convert the string to an integer

edited Aug 14 '20 at 09:26

answered Aug 13 '20 at 14:04

cagcoach

@Tom btw, the correct usage is to also pass in the radix, eg: `parseInt(a, 10)` – Nick Parsons Aug 13 '20 at 14:32

score 0 · Answer 2 · answered Aug 13 '20 at 14:04

0

as stated in the comment, all values from inputs are strings, so you need to

function add() {
var a = parseInt(document.getElementById("a").value);
var b = parseInt(document.getElementById("b").value);
var c = a + b;
}

answered Aug 13 '20 at 14:04

LostJon

2 Answers2