How to ignore unwanted characters from textbox (JavaScript or jQuery) - Stack Overflow

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There's a TextBox that I wanna allow users to just enter numbers & not any alphabetical characters. So how could I ignore those chars entered by end user via JavaScript or jQuery? Notice I don't wanna replace user's entered value by empty string; Instead wanna ignore case if there is any way for it.

There's a TextBox that I wanna allow users to just enter numbers & not any alphabetical characters. So how could I ignore those chars entered by end user via JavaScript or jQuery? Notice I don't wanna replace user's entered value by empty string; Instead wanna ignore case if there is any way for it.

• javascript
• jquery

Share Improve this question Follow edited Dec 15, 2010 at 12:55 jwueller 31k55 gold badges6767 silver badges7070 bronze badges asked Dec 15, 2010 at 12:52 Jerzi.NETJerzi.NET 4111 silver badge44 bronze badges 3

• 2 Your question doesn't make sense. You want to restrict the user input to just numeric values and you want to ignore 'those chars' as entered and you don't want to replace entered value with an empty string (not sure where we are in your process here) and ignore case (of digits!?). Can you re-read your question and please revise it with examples of what you think might be input, how you want to process it and how you want to represent erroneous input to the user. – Lazarus Commented Dec 15, 2010 at 12:57
• Bits of misunderstanding... I wanna restrict user input to just numeric values & if he entered any non-numeric chars, automatically ignore it; Means that specific char not to set all the input to empty string... – Jerzi.NET Commented Dec 16, 2010 at 13:43
• Edit your question. – react_or_angluar Commented Dec 13, 2020 at 0:20

Add a ment  | 

6 Answers 6

Sorted by: Reset to default 7

Try that code:

$("#id").keypress(function (e) {
    //if the letter is not digit then display error and don't type anything
    if ( e.which!=8 && e.which!=0 && (e.which<48 || e.which>57)) {
        return false;
    }
});

reference http://roshanbh..np/2008/04/textbox-accept-only-numbers-digits.html

You want to attach a handler to the textbox's keypress event. In here check the event.which property to find out what key is pressed, and if it's not a number (between keycodes 48 and 57) return false, which will cancel the default behaviour of typing in the textbox.

$("input").keypress(function (e) {
    if (e.which < 48 || e.which > 57)
        return false;
});

I would not remend intercepting keystrokes, allow the user to type whatever he/she wants, and validate on user action (submit/select etc).

Look at this jQuery plugin for instance: http://bassistance.de/jquery-plugins/jquery-plugin-validation/

you said you didn't want to include alphabetical then you said you just want to ignore case? what do you need to do?

You can ignore lower case in JS by using string.toLowerCase()

For numeric-only I use this jQuery extension/plug in

http://www.texotela.co.uk/code/jquery/numeric/

In above options we can prevent the user from keyboard, but what if the user paste something, it will not restrict user to not paste any special character.

For example we are restricting it from keyboard with proper error msg

<script type="text/javascript">
    $(function () {
        $("#package").keypress(function (e) {
            var keyCode = e.keyCode || e.which;

            $("#lblError").html("");

            //Regex for Valid Characters i.e. Alphabets and Numbers.
            var regex = /^[A-Za-z0-9]+$/;

            //Validate TextBox value against the Regex.
            var isValid = regex.test(String.fromCharCode(keyCode));
            if (!isValid) {
                $("#lblError").html("Only Alphabets and Numbers allowed.");
            }
            else
            {
                $("#lblError").html("");
            }

            return isValid;
        });
    });
</script>

Now let's prevent it from pasting special character.

$('#package').bind("paste",function(){  
   var data= $('#package').val() ;
   var removedNotAllowed = data.replace(/[^ws]/gi, '');
   $( '#package' ).val(removedNotAllowed);
   $("#lblError").html("Only Alphabets and Numbers allowed.");
});

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