Extension Methods return value in Swift

Question

I am new to Swift 2. Being learning extension, which I found it is pretty cool feature compared with OC.

An example from apple developer: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Extensions.html

extension Int {
    mutating func square() {
        self = self * self
    }
}
var someInt = 3
someInt.square()
// someInt is now 9

So I was thinking, is it possible to have extension to return value like this:

extension Int {
    func square() {
        return self * self
    }
}
var someInt = 3
someInt.square()
//ERROR: error: no '*' candidates produce the expected contextual result type '()'

My question is how to return a value within an extension? Thanks

http://stackoverflow.com/a/26836477/2303865 – Leo Dabus Apr 11 '16 at 06:08 — Leo Dabus, Apr 11 '16 at 06:08

score 4 · Accepted Answer · answered Apr 11 '16 at 05:51

4

Just like with any other function, you'd need to specify the return type.

extension Int {
    func squared() -> Int {
        return self * self
    }
}
let someInt = 3
let square = someInt.squared()

answered Apr 11 '16 at 05:51

Thilo

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Extension Methods return value in Swift

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