JavaScript first program

Let's write our first JavaScript program. Here it is:

html<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>My first program</title>
    <script>
      alert('Hello, world!');
    </script>
  </head>
  <body>
    my first program
  </body>
</html>

Copy the above code and insert it in an HTML file. Open this file in a browser and you will see a dialog box with text.