Learn JavaScript. How to display a message in a pop up window?


Here’s the source code:

    alert ("It works!");

alert will open a pop-up window, and it will display the text that’s inside “”. In our case, that text is It works!.

You can see a live demo here.
Software used in the demo:
LUNLUN44 (version 2018.02.09): http://LUNLUN.COM/44
Mozilla Firefox (version 62.0): https://www.mozilla.org/en-US/firefox/new/