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# Swift Closures: Using Filter challenge task 1 of 2 is wrong how?

"Challenge Task #1: Define a function, named isOdd, to check if a number is odd. The function takes a number and returns either true or false depending on if the number is odd or not."

I know I am reading this wrong as the function "[inserts] a number and returns [using a return bool] with true or false." I am confused as to how I insert the constant "numbers" to return a bool, which I think is what the question is asking for. Thanks!

filter.swift
```let numbers = [Int](0...50)

func isOdd() -> Bool {
return i % 2 == 0
}

let oddNumber = numbers.filter(isOdd)
```

PLUS
```// Check your syntax!
// Your checking if a number is odd and returning true if correct.

func isOdd(i:Int) -> Bool {

return i % 2 != 0

}

isOdd(3)     // True
isOdd(2)     // False
```

Thanks so much! I did have the "i" in the return question, don't know why it had changed to an integer when I posted the question. It needed to be force unwrapped with the "!=" which did it. Thanks again for the quick response Chris!

PLUS

!= is not unwrapping an optional.

```return i % 2 != 0
```

The function is stating if I take a number and divide it by two is the remainder not equal to 0. If this is the case return true other wise return false.

if we wanted to check for even number...

```return i % 2 == 0
```