Factorial

factorial.js

// Factorial
// Reduce
var number = 7;
	arr = [];

for (var x = 1; x <= number; x++) {
	arr.push(x);
}

alert(arr.reduce(function (a, x) {
	return a * x;
}));


// Recursive
function fact(x) {
	if (x === 1) {
		return 1;
	}

	return x * fact(x - 1);
}

alert(fact(number));

// Loop
var factorial = 1;
for (var x = 1; x <= number; x++) {
	factorial *= x;
}

alert(factorial);