Question

I use this pattern to check for numbers only in a quantity field from 0 to whatever. how can I make the code not allow 012, 010.. etc I mean the starting zero, but still allow 0 as standalone number.

0, 1, 10, 1, etc. are ok,

but not allow 012, 005, etc.

Is there a pattern that does that?

Here is my code but the problem with it, it removes the 0, even if it is not leading in number which I want to avoid. I want to allow the 0 as standalone number in my field.

$('.td-qnt input').live('change keyup blur', function(e) {
    var re = /^[0-9]\d*$/;
    var str = $(this).val();
    $(this).val(str.replace(/^[ 0]/g,''));
    if (re.test(str)){
        var price = $(this).parent().parent().prev('td').html();
        var realprice = price.replace(/[^0-9\.]/g,'');  
        var result = realprice * str;
        var subtotal = result.toFixed(2);
        $(this).parent().parent().next('td').html('$'+subtotal);
    } else {
        $(this).parent().parent().next('td').html('$0.00');
        $(this).val('');
    }
});

Answer 1

"" + parseFloat(str)

Works out what the numerica value is, then makes it a string again. Bingo, no leading zeros.