how to make email validation in javascript and html code example

Example 1: email validation in javascript

/* JavaScript: validating email address */

isValidEmail("[email protected]"); // true

function isValidEmail(email) {
	var emailRegex = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
	return !!email && typeof email === 'string'
		&& email.match(emailformat)};
};

Example 2: javascript email validation

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());
}