Question

I’ve got a javascript function that adds one to a quantity if the current value is less than another value. Here is the javascript function:

function addQty()
{
    if(document.getElementById("quantity").value < document.getElementById("stock").value)
        document.getElementById("quantity").value++;
    else
        return;
}

And here are the form elements that the values are taken from:

<input type='text' id="quantity" name='quantity' value ='0' />
<input type='hidden' id="stock" name="stock" value="<?php echo $adjustedStock; ?>" />

So basically the user can add one to their quantity of a product to order only if there is enough in stock.

Now, this works absolutely fine if the number in stock is 1-9, but if the stock level is in double digits, the maximum the user can add to their basket (ie the ‘quantity’ in the code) returns as the first digit + 1. So if the stock is 13 then the max quantity is 2, or if the stock is 63 the max quantity is 7.

I’ve tried converting the integer value of $adjustedStock to a string before it is used in the form as I read sometimes browsers can behave weirdly in this situation, but this didn’t work. Any ideas why this is happening?

Thanks in advance!

Answer 1

Form element values are strings. Use parseInt or convert to a number some other way.