<!doctype html> <html> <head> <meta charset="UTF-8"> <title>My Web Page</title> <script> alert('hello world!'); </script> </head>
Note:
On the upper right side corner three buttons are given:
![This image has an empty alt attribute; its file name is buttons.png](http://learnprogramo.com/wp-content/uploads/2020/05/buttons.png)
The first button is used to run and execute the code.
Second Button is used for full screen mode.
And the third button is used to copy the Javascript code.