Question

I am a newbie for jquery and currently have a problem on jquery validation. Here is my codes:

jQuery(function(){
                jQuery("#qty").validate({
                    expression: "if (VAL) return true; else return false;",
                    message: "please enter buying amount"
                });
                jQuery("#qty").validate({
                    expression: "if (!isNaN(VAL)) return true; else return false;",
                    message: "Only integer is valid for amount"
                });

                jQuery("#qty").validate({
                    expression: "if (VAL > 0) return true; else return false;",
                    message: "At least buy 1 share"
                });
                jQuery("#qty").validate({
                    expression: "if (VAL <= jQuery('#division').val()) return true; else return false;",
                    message: "You have insufficient amount to purchase"
                });

and another relevant part:

<td><input type="text" name="quantity" size="10" id="qty" value=""/>
<?php 
$division = $available/$rate;
?>

Now the problem is I cannot detect whether the quantity input is decimal. If it is decimal, I want to show error message: only integer is valid for amount. And also, when I compare the quantity input to $division, no matter what positive integer I enter, it will always show the error message “you have insufficient amount to purchase”. Can anyone give me some advice? Say thank you in advance!

Answer 1

You can use this methodology to know the number is not decimal

jQuery("#qty").validate({
     expression: "if (!isNaN(VAL) && (parseFloat(VAL)==parseInt(VAL))) return true; else return false;",
     message: "Only integer is valid for amount"
 });

and in terms of comparison parse the value in to Int i.e.

jQuery("#qty").validate({
   expression: "if (parseInt(VAL, 10) <= parseInt(jQuery('#division').val(), 10)) return true; else return false;",
   message: "You have insufficient amount to purchase"
});

and to prevent leading 0 you could use

jQuery("#qty").validate({
   expression: "if (VAL.substr(0,1) != '0') return true; else return false;",
   message: "Leading zero is not allowed"
});