Printing optional variable

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You have to understand what an Optional really is. Many Swift beginners think var age: Int? means that age is an Int which may or may not have a value. But it means that age is an Optional which may or may not hold an Int.

Inside your description() function you don’t print the Int, but instead you print the Optional. If you want to print the Int you have to unwrap the Optional. You can use “optional binding” to unwrap an Optional:

if let a = age {
 // a is an Int
}

If you are sure that the Optional holds an object, you can use “forced unwrapping”:

let a = age!

Or in your example, since you already have a test for nil in the description function, you can just change it to:

func description() -> String {
    return age != nil ? "\(name) is \(age!) years old." : "\(name) hides his age."
}

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