Ilja Ilja - 1 year ago 91
Javascript Question

Check if correct e-mail was entered

I have a field for users to write their e-mail address in. It is optional, so I need to first check if something was entered in the field, if nothing was entered then do nothing, but if something was entered than check if it is an e-mail.

Right now I'm at this point

var email = $("input#sc_email").val();
if (email == "") {
// If e-mail field is empty do nothing
} else {
// If something was entered
// [CODE HERE] Check if valid e-mail was entered, if not show error message
$("label#email_error").show(); //error message
$("input#sc_email").focus(); //focus on email field
return false;

I'm not even sure if that is right, but I think it is. Right now I need help with gaps in code, I marked them as
. Could anyone suggest a solution please.

Answer Source

You could use the jQuery validate plugin for this, but if you only want to check the validity of an email address in one field, that is a little bit of overkill.

Instead, the regular expression in the function below will make sure the format of the email address is correct, should a value have been entered.

var email = $("input#sc_email").val();  

if (email !== "") {  // If something was entered
    if (!isValidEmailAddress(email)) {
        $("label#email_error").show(); //error message
        $("input#sc_email").focus();   //focus on email field
        return false;  

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^(("[\w-+\s]+")|([\w-+]+(?:\.[\w-+]+)*)|("[\w-+\s]+")([\w-+]+(?:\.[\w-+]+)*))(@((?:[\w-+]+\.)*\w[\w-+]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][\d]\.|1[\d]{2}\.|[\d]{1,2}\.))((25[0-5]|2[0-4][\d]|1[\d]{2}|[\d]{1,2})\.){2}(25[0-5]|2[0-4][\d]|1[\d]{2}|[\d]{1,2})\]?$)/i);
    return pattern.test(emailAddress);
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