JSFiddle - React, Tailwind, and code Playground

by devangkantharia

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.7/jquery.validate.min.js"></script>
<form action="#">
    <input id="number" name="number" maxlength="4" />
    <input type="submit" id="submit" name="submit" />
</form>

JavaScript

$.validator.addMethod("custom_number", function(value, element) {
    return this.optional(element) || value === "NA" || 
        value.match(/^[0-9,\+-]+$/);
}, "Please enter a valid number, or 'NA'");

$("form").validate({
    rules: {
        number: {
            required: true,
            custom_number: true,
            minlength: 4
        }
    } 
});