Functions in Swift (bottom)

Learning from the Geek Academy: functions in Swift

Tool: Xcode6.4

Directly on the basis of the sample code, more knocks more experience will have a harvest: hundred see not like a knock, a knock will

1 Import Foundation2 3 /*********** nested function *************/4Func Getmathfunc (#type: String), (INT)int{5Func squre (Num:int)int{6         returnnum*Num7     }8Func Cube (num:int)int{9         returnnum*num*NumTen     } One     Switch(type) { A          Case "Square": -         returnsqure -     default: the         returnCube -     } - } -var mathfunc = Getmathfunc (type:" Other") +println (Mathfunc (4)) - //because nested functions only work inside the function inside the outer function, using closures simplifies this nested function +  A /*********** Closure Package *************/ at /* - {(formal parameter list)--(return value) in - Executable Statements - } - */ -Func getmathfunc_1 (#type: String), (INT)int{ in //func squre (num:int), int{ - //return Num*num to //    } + //func Cube (num:int), int{ - //return Num*num*num the //    } *     Switch(type) { $      Case "Square":Panax Notoginseng         return { -(Num:int), Intinch the             returnNum *Num +         } A     default: the         return { +(Num:int)->intinch -             returnnum * num *Num $         } $     } - } -var mathfunc_1 = getmathfunc_1 (type:" Other") theprintln (Mathfunc_1 (5)) - //infer types with contextWuyivar squre1: (int), int = {(num)inch returnnum*num} theprintln (Squre1 (8)) -var squre2: (int), int = {numinch returnnum*num} Wuprintln (Squre2 (9)) - //omit formal parameter name, by $0,$1 ... to reference the first, second argument Aboutvar squre3: (int), int = {$0* $0} $println (Squre3 (Ten)) -  - //The classic use of closures -var result:int = { Avar result =1 +      forIinch 1...$1{ theResult *= $0 -     } $     returnresult the}(4,3) the println (Result) the  the //trailing closures -Func someFunction (NUM:INT,FN: (INT)()){ in     //Execute Code the}//The first parameter is an integer and the second parameter is a closure the //Call this function: SomeFunction (20,{}) About //format for calling functions with trailing closures: someFunction {} the  the //a variable or constant in the capture context theFunc Makearr (ele:string),[string]{ +     //Create an array that does not contain any elements -var arr: [String] = [] theFunc addelement ()[string]{Bayi         //adds an element to the ARR array the arr.append (ele) the         returnarr -     } -     returnaddelement the}

Functions in Swift (bottom)