Form Validation
by Nikita Elsakov
HTML
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Required meta tags always come first -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.5/css/bootstrap.min.css" integrity="sha384-AysaV+vQoT3kOAXZkl02PThvDr8HYKPZhNT5h/CXfBThSRXQ6jW5DO2ekP5ViFdi" crossorigin="anonymous">
</head>
<body>
<div class="container">
<form>
<div class="form-group">
<label for="email">Email address</label>
<input type="email" class="form-control" id="email" placeholder="Enter email">
</div>
<div class="form-group">
<label for="password">Password</label>
<input type="password" class="form-control" id="password" placeholder="Password">
</div>
<button class="btn btn-primary" type="submit" id="submit">Sign Up</button>
</form>
</div>
</script>
</body>
</html>
JavaScript
function isEmail(email) {
var regex = /^([a-zA-Z0-9_.+-])+\@(([a-zA-Z0-9-])+\.)+([a-zA-Z0-9]{2,4})+$/;
return regex.test(email);
}
$("#submit").click(function () {
var errMsg = "";
if (isEmail($("#email").val()) == false) {
errMsg += "<p>Your email address is not valid</p>";
}
if ($("#password").val() == "") {
errMsg += "<p>Your password is not valid</p>";
}
alert(errMsg);
});