In this blog post, I will share how to create html form validation using Javascript code. JavaScript provides the facility to validate the form on the client-side so data processing. Most of the web developers prefer JavaScript validation.
Using JavaScript, you can validate name, password, email, date, mobile numbers and more fields. Keep reading on Simple jQuery Form Validation Example, How to make comment box in Html and CSS
Html Form Validation using JavaScript Code
The following example will demonstrate how to validate username, email, and password. They can’t be empty. Here, we are validating the form on form submit. The user will not be forwarded to the next page until the given values are correct.
index.html
JavaScript Form Validation Create Account
Script.js
const form = document.getElementById('form'); const username = document.getElementById('username'); const email = document.getElementById('email'); const password = document.getElementById('password'); const password2 = document.getElementById('password2'); form.addEventListener('submit', e => { e.preventDefault(); checkInputs(); }); function checkInputs() { // trim to remove the whitespaces const usernameValue = username.value.trim(); const emailValue = email.value.trim(); const passwordValue = password.value.trim(); const password2Value = password2.value.trim(); if (usernameValue === '') { setErrorFor(username, 'Username cannot be blank'); } else { setSuccessFor(username); } if (emailValue === '') { setErrorFor(email, 'Email cannot be blank'); } else if (!isEmail(emailValue)) { setErrorFor(email, 'Not a valid email'); } else { setSuccessFor(email); } if (passwordValue === '') { setErrorFor(password, 'Password cannot be blank'); } else { setSuccessFor(password); } if (password2Value === '') { setErrorFor(password2, 'Confirm password cannot be blank'); } else if (passwordValue !== password2Value) { setErrorFor(password2, 'Passwords does not match'); } else { setSuccessFor(password2); } } function setErrorFor(input, message) { const formControl = input.parentElement; const small = formControl.querySelector('small'); formControl.className = 'form-control error'; small.innerText = message; } function setSuccessFor(input) { const formControl = input.parentElement; formControl.className = 'form-control success'; } function isEmail(email) { return /^(([^()\[\]\\.,;:\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,}))$/.test(email); }
Download Source Code
Conclusion
I hope you liked this article on validation in javascript for registration form. I would like to have feedback from my blog readers. Your valuable feedback, question, or comments about this article are always welcome.
The post Html Form Validation using JavaScript Source Code appeared first on DotNetTec.
This post first appeared on Asp Dot Net Tricks And Tips, Dot Net Coding Tips, Google Maps API Developer, please read the originial post: here