Open a new window in Chrome,
then locate the Console tab.
Voila! You now have access to the Chrome V8 Engine. Just like the Node REPL, you can input JavaScript code into the Console tab and the V8 engine will execute it.
Let's try an example.
In the Chrome console,
invoke the function alert with an input string of "Hello world!";
What effect does calling the alert function have?
It will open alert and say Hello world
Now try invoking the function prompt with a string input of "What is your name?" - store the return value of your call to prompt in an variable called myName.
What effect does calling the prompt function have?
It Will open the prompt and asking for the input.
What is the return value of prompt?
prompt() returns a string, or empty string, or null (if Cancel is pressed).