javascript - Check if correct e-mail was entered - Stack Overflow

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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 [CODE HERE]. Could anyone suggest a solution please.

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 [CODE HERE]. Could anyone suggest a solution please.

• javascript
• jquery
• validation

Share Improve this question Follow edited Nov 18, 2016 at 15:23 Rory McCrossan 337k4141 gold badges319319 silver badges350350 bronze badges asked Dec 6, 2011 at 10:31 IljaIlja 46.5k103103 gold badges289289 silver badges525525 bronze badges 2

• possible duplicate of Validate email address in Javascript? – Richard Dalton Commented Dec 6, 2011 at 10:35
• Possible duplicate of Validate email address in JavaScript? – Flummox uses codidact.com Commented Apr 11, 2017 at 14:57

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3 Answers 3

Sorted by: Reset to default 23

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);
};

You could use regular expressions to validate the email address in JavaScript.

function validateEmail(email) { 
    var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\
".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA
-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
}

This will, however, only validate that it is a valid email address formatted string. [email protected] would be valid, even if no-one actually has that email address.

Have a look at this question.

I would recommend validation both at client side and at server side, you could simply use this code:

alert(/\S+@\S+\.\S+/.test('asdasd@[email protected]'));
alert(/\S+@\S+\.\S+/.test('[email protected]'));

but importantly, use server side validation and methodology, like sending click-link-mail, to verify your client email address or mailing random number etc.

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