how to validate the email id in javascript code example

Example 1: javascript regex email

function validateEmail (emailAdress)
{
  let regexEmail = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
  if (emailAdress.match(regexEmail)) {
    return true; 
  } else {
    return false; 
  }
}

let emailAdress = "[email protected]";
console.log(validateEmail(emailAdress));

Example 2: validate email javascript regex

function validateEmail(email) {
    const 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(String(email).toLowerCase());
}

Example 3: how to validate email in node js

var emailRegex = /^[-!#$%&'*+\/0-9=?A-Z^_a-z{|}~](\.?[-!#$%&'*+\/0-9=?A-Z^_a-z`{|}~])*@[a-zA-Z0-9](-*\.?[a-zA-Z0-9])*\.[a-zA-Z](-?[a-zA-Z0-9])+$/;

function isEmailValid(email) {
    if (!email)
        return false;

    if(email.length>254)
        return false;

    var valid = emailRegex.test(email);
    if(!valid)
        return false;

    // Further checking of some things regex can't handle
    var parts = email.split("@");
    if(parts[0].length>64)
        return false;

    var domainParts = parts[1].split(".");
    if(domainParts.some(function(part) { return part.length>63; }))
        return false;

    return true;
}