HTML
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Hello World in JavaScript</title>
</head>
<body>
<h1>Demo: Hello World in JavaScript</h1>
<p><strong>NOTE: To display the alert() message, view output in the full window!</strong></p>
<p><strong>To display the console.log() message, view output in the web console log!</strong></p>
<p id="para"></p>
<!-- JavaScript Code begins here -->
<script>
// Using alert() method - alert box with a message
alert("Hello World - By alert() method");
// Using write() method - write content to the Document
document.write("Hello World - By write() method");
// Using log() method - write message to the console
console.log("Hello World - By console.log() method");
// Using DOM selection & manipulation
document.getElementById("para").innerHTML =
"Hello World - By DOM selection & manipulation";
</script>
</body>
</html>