As a variable:
var closureName: (ParameterTypes) -> (ReturnType)
As an optional variable:
var closureName: ((ParameterTypes) -> (ReturnType))?
As a constant:
let closureName: ClosureType = { ... }
As an argument to a function call:
func({(ParameterTypes) -> (ReturnType) in statements})
As a function parameter:
array.sort({ (item1: Int, item2: Int) -> Bool in return item1 < item2 })
As a function parameter with implied types:
array.sort({ (item1, item2) -> Bool in return item1 < item2 })
As a function parameter with implied return type:
array.sort({ (item1, item2) in return item1 < item2 })
As the last function parameter:
array.sort { (item1, item2) in return item1 < item2 }
As the last parameter, using shorthand argument names:
array.sort { return $0 < $1 }
As the last parameter, with an implied return value:
array.sort { $0 < $1 }
As the last parameter, as a reference to an existing function:
array.sort(<)
As a function parameter with explicit capture semantics:
array.sort({ [unowned self] (item1: Int, item2: Int) -> Bool in return item1 < item2 })
As a function parameter with explicit capture semantics and inferred parameters / return type:
array.sort({ [unowned self] in return item1 < item2 })
