Why i don't getting the right output when using console.log instead of return?

Question

https://code.sololearn.com/WMA4dP2Lv73F/?ref=app

Answer 1

You don't get a number because the factorial function returns undefined. Multiplying undefined by a number is giving back NaN.

Test this by running this code:
let func = function() {
//empty
}

console.log(func());
console.log(func() * 1);

//returns undefined and NaN

Answer 2

console.log() outputs to the console. That is all.

return returns values from a function.

Answer 3

Because you are returning nothing.

Answer 4

Outputting to the console. That's all. It doesn't return anything.

Answer 5

No, they do different things

Answer 6

But why the factorial function returns undefined instead of the required thing

Answer 7

So what is the meaning of console.log(factorial(n-1)*n) and console.log(1) here