It should not allow leading zeroes, like 099. Allowed values should be like these: 35, 99, 1, 2, 3, 100.

This is What I tried:

$('#createCoupon_discountAmount').bind('input propertychange', function () {
    $(this).val($(this).val().replace(/(\d\d?|100)\Z/g, ''));
});  

It should not allow leading zeroes, like 099. Allowed values should be like these: 35, 99, 1, 2, 3, 100.

This is What I tried:

$('#createCoupon_discountAmount').bind('input propertychange', function () {
    $(this).val($(this).val().replace(/(\d\d?|100)\Z/g, ''));
});  

• javascript
• jquery
• regex

• @RoryMcCrossan : its not working .. it accepts leading zero. – Kishore Commented Aug 31, 2016 at 9:11
• ^[1-9][0-9]?$|^100$ this would be a valid regex for your problem. just specify what you would like to allow for the first number. – Florin M Commented Aug 31, 2016 at 9:22
• Just a note that regex is not really the most suitable tool for this task. – JJJ Commented Aug 31, 2016 at 9:31
• for percentage a text box should allow only digit from 0 to 100. maxLength is 3. – Kishore Commented Aug 31, 2016 at 9:44

4 Answers 4

The regex that I would use for this is the following, but I'm not sure if it an optimal one:

^([0-9]|([1-9][0-9])|100)$

We create three groups and we always match from the beginning of the string to the end. The first group we capture is [0-9]to get the first 10 numbers (0-9). The second group we capture those numbers twice, to get all numbers from 10 -> 99. And finally we just match 100 as well.

This version is shorter and possibly more efficient /^([1-9]?\d|100)$/

If you want to remove leading zeros, try removing them from the beginning position using ^0+ i.e. match string starting with one or more zeros.

$(this).val().replace(/^0+/g, '')

Just multiply the value by 1 and it will give you a perfect number