Question

I know this question will be closed because I studied many example of this but please see I think I am doing something different.

I coded my server side PHP email validation with this:

if (!filter_var($user_new_email, FILTER_VALIDATE_EMAIL)) {
        $errors .="Email,"; 
        $pass    = false;
             }

My client side email validation is:

function validateEmail(txtEmail){
 var a = document.getElementById(txtEmail).value;
 var filter = /^[a-zA-Z0-9_.-]+@[a-zA-Z0-9]+[a-zA-Z0-9.-]+[a-zA-Z0-9]+.[a-z]{1,4}$/;
   if(filter.test(a)){
    return true;
   }
   else{
    return false;
   }

So in my client side if I enter only username@domain (without .com), it’s valid. I don’t want that.

I need the same validaton in both client and serverside.
How to update my regular expression in JavaScript?

Answer 1

Just escape the last ‘.’ (dot) in your regex. When not escaped or inside brackets, a dot matches any character except new line. So the correct value for filter is:

var filter = /^[a-zA-Z0-9_.-]+@[a-zA-Z0-9]+[a-zA-Z0-9.-]+[a-zA-Z0-9]+\.[a-z]{1,4}$/;