What are the DOM methods available for constraint validation

The below DOM methods are available for constraint validation on an invalid input,

1. checkValidity(): It returns true if an input element contains valid data.
2. setCustomValidity(): It is used to set the validationMessage property of an input element. Let's take an user login form with DOM validations

function myFunction() {
var userName = document.getElementById("uname");
if (!userName.checkValidity()) {
document.getElementById("message").innerHTML =
userName.validationMessage;
} else {
document.getElementById("message").innerHTML =
"Entered a valid username";
}
}