Validating email and password using javascript

Question

I know its good to use serverside validation for security, except this is just to get my head around validation.

My efforts so far have amounted to the following

function validateUser()
{
    var x=document.forms["myForm"]["email"].value;
    var y=document.forms["myForm"]["password"].value;
    var atpos=x.indexOf("@");
    var dotpos=x.lastIndexOf(".");
    var uppercase = password.match(/[A-Z]/)
    var lowercase = password.match(/[a-z]/g)
    var number = password.match(/[0-9]/g)
    if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
    {
    alert("Not a valid e-mail address or password");
    return false;
    }else{ 
    alert("Valid Email Address and Password");
    return true;

    }
    }

Basically, I need an alert box to pop up when the password doesn't have at least 1 lowercase, uppercase and a number. So far my code is just throwing an error when the email is in the wrong format. What do I add to the if statement to check the password characters?

Thanks in advance,

James

Answer 1

Few issues we have in your current implementation:

a. The error you're likely getting is that password is undefined.

Right now you're doing:

var y=document.forms["myForm"]["password"].value;

but you refer to it as "password" further on:

var uppercase = password.match(/[A-Z]/)
var lowercase = password.match(/[a-z]/g)

change the var y to:

var password=document.forms["myForm"]["password"].value;

b. To validate email, you should use a Regex such as:

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,}))$/;

var isValidEmail = re.test(email);

c. To check for the password rules, you should just rely on the regular expressions you have in place already (and strip out the atpos, dotpos usage - that makes it much more complicated than it even needs to be).

Example:

var email='me@mailinator.com';
var password='test-P1assword';
var hasUpper = password.match(/[A-Z]/)
var hasLower = password.match(/[a-z]/g)
var hasNumber = password.match(/[0-9]/g)

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,}))$/;

var isValidEmail = re.test(email);

if (isValidEmail && hasUpper && hasLower && hasNumber) {
    alert("Valid Email Address and Password");
    return true;
} else { 
    alert("Not a valid e-mail address or password");
    return false;
}

JSFiddle example, complete with Regex to validate email AND password: http://jsfiddle.net/4hH3T/2/

The regex was taken from: Validate email address in JavaScript?

Answer 2

you can use regex to validate.

 var reg=/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*(_|[^\w])).+$/;
 var isValid=reg.test(inputemail);