how to check validation email address in javascript on submit code example

Example 1: how to validate an email address in javascript

function validateEmail(email) 
    {
        var re = /\S+@\S+\.\S+/;
        return re.test(email);
    }
    
console.log(validateEmail('[email protected]'));

Example 2: code for email verification in front end using javascript

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());
}