06_factorial_A.js

function factorialOfNum(num) {
    let result = 1;

    if(num == null || num == undefined){
        console.log(`${num} - Invalid Input.`);
        return;
    }
    for (let i = num; i > 0; i--) {
        result = result * i;
    }

    console.log(`The Factorial of ${num} is ${result}.`);

    // if(num == 0)
    //     return 1;

    // return num * factorialOfNum(num - 1);
}

factorialOfNum(5);
factorialOfNum(3);
factorialOfNum(null);
factorialOfNum(8);
factorialOfNum(undefined);
factorialOfNum(9);
factorialOfNum(0);