​x
 
<!DOCTYPE html>
<html>
<body>
​
<h2>JavaScript Objects</h2>
<p id="demo"></p>
​
<script>
const person = {
  firstName: "John",
  lastName: "Doe",
  id: 5566,
};
person.name = function() {
  return (this.firstName + " " + this.lastName).toUpperCase();
};
​
document.getElementById("demo").innerHTML =
"My father is " + person.name(); 
</script>
​
</body>
</html>
​