Email Address Validator function that uses Regular Expressions

emailUtilFunctions.js

/**
 * Given a string, validates an email address
 * @param {String} emailString: the user submitted email address
 * @returns {Boolean} true/false: indicates if the email address is valid or not
 * */
const isEmailAddressValid = (emailString) => {
    const regExpStr = /^(([^<>()\[\]\\.,;:\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 regExpStr.test(emailString);
};