How to validate email in Jquery?

问题

I have written the following contact form validation script. How can I validate a email field?

<style type="text/css">
    div.contactForm { width:370px; margin:0 auto; }
    form.contactUs label { display:block; }
    form.contactUs input { margin-bottom:10px; }
    input.submit { margin-top:10px; }
    input.error { background:#FF9B9B; border:1px solid red; }
    div.errorMessage { color:#f00; padding:0 0 20px; }
</style>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>

<script type="text/javascript">
    $(document).ready(function() {
        $('.errorMessage').hide();
        $('.submit').click(function() {

            var name = $('input.name').val();
            var email = $('input.email').val();
            var phone = $('input.phone').val();

            if (name == '') {
                $('input.name').addClass('error');
                $('input.name').keypress(function(){
                    $('input.name').removeClass('error');
                });
            }
            if (email == '') {
                $('input.email').addClass('error');
                $('input.email').keypress(function(){
                    $('input.email').removeClass('error');
                });
            }
            if (phone == '') {
                $('input.phone').addClass('error');
                $('input.phone').keypress(function(){
                    $('input.phone').removeClass('error');
                });
            }
            if (name == '' || email == '' || phone == '') {
                $('.errorMessage').fadeIn('medium');
                return false;
            }

        });
    });
</script>

<div class="contactForm">

<h2>Contact Us</h2>

<div class="errorMessage">Please enter all required fields.</div>

<form action="http://google.com" method="post" class="contactUs">

    <label>Name <em>(required)</em></label>
    <input type="text" name="name" class="name" size="30" />

    <label>Email <em>(valid email required)</em></label>
    <input type="text" name="email" class="email" size="30" />

    <label>Phone <em>(required)</em></label>
    <input type="text" name="phone" class="phone" size="30" />

    <label>Message</label>
    <textarea name="message" cols="40" rows="10"></textarea>

    <br />
    <input type="submit" name="submit" value="Submit" class="submit" />

</form>

</div><!--contactForm-->

EDIT

By validation I mean the entered value must contain a " @ " and a " . " at proper place.

Also I don't want to use any additional plugins.

回答1:

You can use RegEx if you don't want to use any plugins.

var testEmail = /^[A-Z0-9._%+-]+@([A-Z0-9-]+\.)+[A-Z]{2,4}$/i;
if (testEmail.test(valueToTest))
    // Do whatever if it passes.
else
    // Do whatever if it fails.

This will get you most emails. An interesting read about validating emails with RegEx.

You can test the script here: http://jsfiddle.net/EFfCa/

回答2:

If you really don't want to use a plugin I've found this method to be quite good:

function validateEmail(email) {
    var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
    if( !emailReg.test( email ) ) {
        return false;
    } else {
        return true;
    }
}

JSFIDDLE

http://thejimgaudet.com/articles/support/web/jquery-e-mail-validation-without-a-plugin/

回答3:

I'm currently using ketchup for form validation. There's also bassassist's plugin. Check a plugin, it will save you hours of regex-writing code.

回答4:

Change your input.email block as this:

            if (email == '') {
            $('input.email').addClass('error');
            $('input.email').keypress(function(){
                $('input.email').removeClass('error');
            });
            $('input.email').focusout(function(){
                $('input.email').filter(function(){
                    return this.value.match(/your email regex/);
                }).addClass('error');
            });
        }

Explaination: Add focusout action to input.email form element, validates the email string using RFC822 standard. If it can't pass then add the 'error' class.

I have not tested this on my browser but it should work for jQuery > 1.4.

EDIT: I've removed the regex, place your favorite one there.

来源：https://stackoverflow.com/questions/3663968/how-to-validate-email-in-jquery