factorial

Question

Hello,
I am trying to right a factorial func, so far I have
var n = Int(readLine()!)!
func factorial(input: Int) -> Int {
    var z = input
        for i in (0 ..< input).reverse() {
            z *= i
        }
     return(z)
}
print(factorial(n))
The issue i am having is that for some reason I cannot pull the z from the equation to use. I tried putting the return in the loop but that ends it immediately?
Can anyone assist?

ianhan3 · Answer

A recursive function is what you want here. You can run your function inside your function decrementing the number each time by 1. Once the parameter number hits zero, the if statement is true and you simply return 1 instead of multiplying your correct factorial by 0, making it 0.
```swift
func factorialize(number: Int) -> Int {
    if (number == 0) {
        return 1
    }
    return number * factorialize(number - 1);
}
factorialize(5);
//returns 120
```

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William Forbes

William Forbes

factorial

1 Answer

ianhan3

ianhan3