guard let vs. if nil

guard-let-vs-if-nil.swift

//: guard let example

func printifnonnil(text: String?) {
    if text == nil {
        return
    }
    // syntatically, unwrapping still required since text is still an optional
    print(text!) 
}

func printguard(text: String?) {
    guard let text = text else {
        return
    }
    // guranteed that text is not an optional
    print(text)
}

printifnonnil(text: "hello")
printifnonnil(text: nil)
printguard(text: "hello")
printguard(text: nil)