Check if an email is valid

var email = "johndoe@gmail.com";
    var emailRegex = /^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$/;
    if (emailRegex.test(email)) {
        console.log(email + " is valid.");
    } else {
        console.log(email + " is not valid.");
    }