naming.js

function validateEmail(email) {
  // validate and return true or false
}

function isEmailValid(email) {
  // validate and return true or false
}

function emailIsValid(email) {
  // validate and return true or false
}

function isEmail(email) {
  // validate and return true or false
}

function isValidEmail (email) {
  // validate and return true or false
}

const email = "[email protected]";

if (validateEmail(email)) {
  // do some stuff
}
if (isEmailValid(email)) {
  // do some stuff
}
if (emailIsValid(email)) {
  // do some stuff
}
if (isEmail(email)) {
  // do some stuff
}
if (isValidEmail(email)) {
  // do some stuff
}