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?
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?
What is the return value of prompt
alert("Hello World!") the pop up box:chrome://new-tab-page says Hello world! i press ok button, return undefined.the pop up box pauses JS execution until press ok <.undefined myName = prompt("What is your name") <.'ping' Warning: Don’t paste code into the DevTools Console that you don’t understand or haven’t reviewed yourself. This could allow attackers to steal your identity or take control of your computer. Please type ‘allow pasting’ below and press Enter to allow pasting. allow pasting let myName = prompt("What is your name?"); the pop up box:chrome://new-tab-page says, i ignore blue box just press cancel, <.console.log("Your name is:", myName); VM255:2 Your name is: null undefined let myName = prompt("What is your name?"); in pop up box: chrome://new-tab-page says, i put my name'ping' in blue box then press ok <.console.log("Your name is:", myName); VM259:2 Your name is: ping undefined The value returned from prompt() is stored in the variable myName. The pop up box pauses the JS execution until i press the button either'cancel' or put my name before press'OK'.