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JavaScript Regular Expressions in JavaScript Validating a Form Validating a Phone Number

it did not work for me, why?

const usernameInput = document.getElementById("username"); const passwordInput = document.getElementById("password"); const telephoneInput = document.getElementById("telephone"); const emailInput = document.getElementById("email");


  • */

// Can only contain letters a-z in lowercase function isValidUsername(username) { return/^[a-z]+$/.test(username); }

// Must contain a lowercase, uppercase letter and a number function isValidPassword(password) { return/[a-z]/.test(password) && /[A-Z]/.test(password) && /[0-9]/.test(password) && /^(?=.\d)(?=.[a-z])(?=.[A-Z]).$/.test(password); }

// The telephone number must be in the format of (555) 555-5555 function isValidTelephone(telephone) { return /^(\d{3})\s{3}-\d{4}$/.test(telephone); }

// Must be a valid email address function isValidEmail(email) {}


  • */

function formatTelephone(text) {}


  • */

function showOrHideTip(show, element) { // show element when show is true, hide when false if (show) { element.style.display = "inherit"; } else { element.style.display = "none"; } }

function createListener(validator) { return e => { const text = e.target.value; const valid = validator(text); const showTip = text !== "" && !valid; const tooltip = e.target.nextElementSibling; showOrHideTip(showTip, tooltip); }; }

usernameInput.addEventListener("input", createListener(isValidUsername));

passwordInput.addEventListener("input", createListener(isValidPassword));

telephoneInput.addEventListener("input", createListener(isValidTelephone));

emailInput.addEventListener("input", createListener(isValidEmail));

olushola oludipe
olushola oludipe
Web Development Techdegree Student 10,948 Points

Hi Karl, In your code you have

^(\d{3})\s{3}-\d{4}$/.test(telephone); }

1.now if you check the first part of your regex you have ^(\d{3}) which is meant to catch (555), you forgot to escape the (. to escape a special character you put \ before the character not after, so it's meant to be like this /^\(. 1b.you made the same mistake after \d{3}. so it's meant to be like this /^\(\d{3}\)\s. this covers the "(555) "of the search

2.you typed\s{3} which means "there white spaces". to fix this add a \d before the {3}. so that part will look like this \s\d{3}- putting everything together the regex should look like this /^\(\d{3}\)\s\d{3}-\d{4}$/.test(telephone). its easy to mistype expression , so thats why it's a good idea to test them on sites like https://www.regexpal.com/ just to make sure they work properly . hope this helps, Good luck