Checking only integer digit using RegEx in JQUERY

Question

I have following code snippet:

    var reg = /^[0-9]$/;

    $('input[type="text"]').keypress(function(){
       console.log(reg.test(parseInt($(this).val())));
    });

When I press any key (digit or other) it always return false. But I can't find out the problem.Please give me some solutions.

Because at the time the handler is executed, the value of the field is not updated yet. It is an empty string (if there is no default value). You can easily test this with: `console.log($(this).val());` — Felix Kling, Apr 24 '11 at 08:18

score 3 · Answer 1 · edited May 23 '17 at 12:01

3

See How to allow only numeric (0-9) in HTML inputbox using jQuery? for a proper solution.

In case you want to do something own, have a look at those plugins anyway. It's very important to not break common things like backspace (or ctrl+c/v/x) as users usually expect those keys to work.

edited May 23 '17 at 12:01

Community

1
1

answered Apr 24 '11 at 08:16

ThiefMaster

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score 1 · Accepted Answer · answered Apr 24 '11 at 08:22

The regex you've created tests for exactly 1 occurance of any digit. It also asserts that it's the begining of the string followed by a single digit, then the end of string.

The keypress event is triggered before actual content is put into the textbox. This should only work for the second key press, because that's when the textbox content .val() yields exactly 1 digit.

If you follow the link posted by @ThiefMaster you'll find the answer to your question. You'll also note that it's using the charCode and keyCode properties of the event object to do validation not the contents of the textbox.

score 0 · Answer 3 · answered Jan 02 '17 at 15:31

 $("#txtBoxID").keypress(function (event) {
            var reg = /[\d\.]/g;
            if (!reg.test((event.key))) {
                return false;
            }                      
        });

I have done like above, I have used keypress and its event and one regular function which will allow user to enter only DIGITS in text box/ input box.

You can check event.key , which give value of key has bee

Checking only integer digit using RegEx in JQUERY

3 Answers3