How to add zero to hidden input?

Question

I want to add zero to a hidden input field when '0' button is pressed. This is html:
<form method="POST">
<input type="hidden" id="code" name="code" >
</form>
And the button:
<button onclick="document.getElementById('code').value+='0';" class="keypad">0</button>
But when i press 0 button, hidden value doesn't change.

Answer 1

Try to log `code.value` in Javascript console, I don't see a reason why `code.value` doesn't change. Here I added logging for `code.value` in the button's 'onclick' attribute. Try and see if it works on your side.

<button onclick="code.value += '0'; console.log(code.value);" class="keypad">0</button>