HTML display result in text (input) field?

Question

I have a simple HTML form, with 3 input field, when you hit = button, it suppose to add 2 numbers that you typed in the first 2 input fields and display result in 3rd filed.

Answer 1

innerHTML sets the text (including html elements) inside an element. Normally we use it for elements like div, span etc to insert other html elements inside it.

For your case you want to set the value of an input element. So you should use the value attribute.

Change innerHTML to value

document.getElementById('add').value = sum;