The "alert" JavaScript file

We will put our code on the head of the HTML file:

It is the simple interaction "alert".

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Example of alert()</title>
    <script>
        alert("Hello world");
    </script>
  </head>
  <body>
  </body>
</html>

Copy and paste the code into your editor to see the output. Save the file in the folder "temporaryFiles". Next, use the the Live preview in the editor or open the file (Ctrl+O) in your Chrome. 

alert popup