console.log() is a function. And afunction is always going to return some value back to the caller. If a return value is not specified, then the function will return back undefined,as inconsole.log().

For example, copy and paste the below code in the console:

function isThisWorking(input) {    console.log("Printing: isThisWorking was called and " + input + " was passed in as an argument.");    return "I am returning this string!";}isThisWorking(3);

So,isThisWorking function will return back"I am returning this string!" in the console, because that's what the function is returning.

But,If we removed the return, it will return back undefined:

function isThisWorking(input) {    console.log("Printing: isThisWorking was called and " + input + " was passed in as an argument.");}isThisWorking(3);

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