Validate that text field is numeric usiung jQuery

I know there isn't any need to add a plugin for this.

But this can be useful if you are doing so many things with numbers. So checkout this plugin at least for a knowledge point of view.

The rest of karim79's answer is super cool.

<!DOCTYPE html>
<html>
    <head>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
        <script type="text/javascript" src="jquery.numeric.js"></script>
    </head>

    <body>
        <form>
            Numbers only:
            <input class="numeric" type="text" />
            Integers only:
            <input class="integer" type="text" />
            No negative values:
            <input class="positive" type="text" />
            No negative values (integer only):
            <input class="positive-integer" type="text" />
            <a href="#" id="remove">Remove numeric</a>
        </form>

        <script type="text/javascript">
            $(".numeric").numeric();

            $(".integer").numeric(false, function() {
                alert("Integers only");
                this.value = "";
                this.focus();
            });

            $(".positive").numeric({ negative: false },
                function() {
                    alert("No negative values");
                    this.value = "";
                    this.focus();
                });

            $(".positive-integer").numeric({ decimal: false, negative: false },
                function() {
                    alert("Positive integers only");
                    this.value = "";
                    this.focus();
                });

            $("#remove").click(
                function(e)
                {
                    e.preventDefault();
                    $(".numeric,.integer,.positive").removeNumeric();
                }
            );
        </script>

    </body>
</html>

Regex isn't needed, nor is plugins

if (isNaN($('#Field').val() / 1) == false) {
    your code here
}

This should work. I would trim the whitespace from the input field first of all:

if($('#Field').val() != "") {
    var value = $('#Field').val().replace(/^\s\s*/, '').replace(/\s\s*$/, '');
    var intRegex = /^\d+$/;
    if(!intRegex.test(value)) {
        errors += "Field must be numeric.<br/>";
        success = false;
    }
} else {
    errors += "Field is blank.</br />";
    success = false;
}

I'm not certain when this was implemented, but currently you can use http://api.jquery.com/jQuery.isNumeric/

if($('#Field').val() != "")
{
    if($.isNumeric($('#Field').val()) {
        errors+= "Field must be numeric.<br/>";
        success = false;
    }
}

Tags:

Jquery

Validation

Recent Posts