How to toggle a boolean value

Paul Hudson    September 2nd 2018    @twostraws

Swift’s booleans have a toggle() method that flip them between true and false. That might sound simple, but the end result makes for much more natural Swift code:

var loggedIn = false
loggedIn.toggle()

This is particularly useful in more complex data structures: myVar.prop1.prop2.enabled.toggle() avoids the potential typing errors that could be caused using manual negation.

If you were curious, the entire code to implement toggle() is only a handful of lines of Swift:

extension Bool {
   mutating func toggle() {
      self = !self
   }
}

Available from iOS 8.0

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