What does the question mark do in this function, and why is it necessary?

Question

func factorial(n: Int) -> Int {
return n == 0 ? 1 : n * factorial(n: n-1)
}

Answer 1

It is a ternary operator. It works like an if statement.

- https://syntaxdb.com/ref/swift/ternary

Answer 2

It is an ternary operator similar to if else clause.

Hope this helps☺️☺️.

Answer 3

In the Factorial formula, all the positive integers must be multiplied between the number that appears in the formula and the number 1)

Example = 7! = 1 * 2 * 3 * 4 * 5 * 6 * 7 = 5040