intermediate
Form Validation
Validate form inputs before submission.
Learn to check form values and prevent submission.
📚 Concepts & Theory
Form Validation
form.addEventListener('submit', (e) => {
if (!input.value) {
e.preventDefault();
// show error
}
});🎯 Your Challenge
Validate that email field is not empty.
📝 Starter Code
JavaScript
// HTML: <form id="myForm"><input id="email"><button>Submit</button></form>
function validateForm() {
// Your code here
}Solution
JavaScript
function validateForm() {
const form = document.getElementById('myForm');
const email = document.getElementById('email');
form.addEventListener('submit', (e) => {
if (!email.value.trim()) {
e.preventDefault();
alert('Email is required!');
}
});
}
validateForm();Explanation
Prevent default if validation fails.
❓ Frequently Asked Questions
Stops form from submitting