How to pass value to js?

Question

JavaScript

For example, there is an input

<input type="text" class="qty-input" name="quantity" size="2" value="1" />

and

<a onclick="addToCart('<?php echo $result['product_id']; ?>', '1');" class="btn btn-cart">Добавить в корзину</a>

Value in input changes, both by +/- and manually entered. So here's how to pass this value to

addToCart('<?php echo $result['product_id']; ?>', '1');

(respectively instead of '1') ?

This is

addToCart('<?php echo $result['product_id']; ?>', document.getElementById('quantity').value);"

I tried, but it takes the initial value of the input, and as I said, its value changes and you need ...

Answer 1

Remove this argument "1" altogether. And inside the function, take the value value of this input.