函数当做返回值
func stepForward(Input:Int)->Int{
return Input+1;
}
func stepBackwardForward(Input:Int)->Int{
return Input-1;
}
func chooseStepFunction(isBack:Bool)->(Int)->Int{
return isBack ? stepForward : stepBackwardForward;
}
var currentValue=4
let move=chooseStepFunction(isBack: currentValue>6)
move(8)函数当做参数
func stepForward(Input:Int)->Int{
return Input+1;
}
func stepBackwardForward(Input:Int)->Int{
return Input-1;
}
func getMathResult(function:(Int)->Int,a:Int){
print("Result:\(function(a))")
}
getMathResult(function: stepForward(Input:), a: 123)
getMathResult(function: stepBackwardForward(Input:), a: 456)无参数无返回值的函数使用
()->()
表示
