Question

I have simple form set up like the following:

<form>
<input type="text" name="first_number" id="first_number" />
</form>

I want to add a button to the form that has an onclick() that gets the value of the text in the input field and sends it to my javascript function called simple_math() that has the parameter “number”. For instance:

<input type="button" onclick="simple_math(document.getElementById('first_number').value)" />

But I know that’s the incorrect syntax. Is this possible? Thank you very much!

Answer 1

Your code is correct, but if you are using the value in a math equation, you may need to use parseInt to convert the value from a string to an integer.

Like so:

<input type="button" onclick="simple_math( parseInt(document.getElementById('first_number').value, 10) )" />