The functions of swift and function pointers, closure closure, and other related contents are introduced

<span style= "FONT-SIZE:24PX;" >//function//demo1 no parameter type func testconcat () {println ("test function");} Testconcat ()//Call Demo1//demo2 Multi-parameter, a return value/* function begins with Func, represents a function v1 represents a parameter, string parameter type, return value type String*/func testconcats (v1 : string,v2:string)->string{return "\ (v1) and \ (v2)";} The function parameter contains the label func testconcatandmark (V1:string,andvalue v2:string,andnumber v3:string)->string{return "\ (v1), \ (v2),    \ (v3) "}//test function func testfunction () {Let V = testconcats (" Hello "," World ");    println (v);    Let V2 = Testconcatandmark ("David", Andvalue: "Dream", Andnumber: "good"); println (v2)}testfunction ()//function returns multivalued func GetInfo (), (String,string,int) {return ("David", "Dream", 100);} Let (V1,v2,v3) =getinfo ();p rintln ("v1=\ (v1), V2=\ (v2), v3=\ (v3)");//function Nesting function func testfunctioninfunction ()->int{var    y = 10;    Func Add () {y+=5;    } add (); return y;} Let V6 = Testfunctioninfunction ();//*******************************//function pointer * * Five-Star Difficulty * * return value is (Int->int), is a function address first in T is the parameter type, and the second int is the return value */fUNC Getfuncpointer (), (int->int) {func addone (num:int)->int{return num+1; Return addone;//returns a function address}var funpointer = Getfuncpointer ();//funpointer is a function pointer var v7 = funpointer (100);//function called Func        Get () (int->string) {func post (count:int)->string{if count>50{return "success"; }else{return "Failed"}} return post;} Let V8 = Get ();//v8 gets the address of the get () function Let V9 = V8 ();//v9 gets the return value of the Get function//function pointer/address as a parameter, function as argument to function, function transfer </span>

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<span style= "FONT-SIZE:24PX;" >//closure is a difficult problem, the function of closure is mainly the communication between functions and functions, a bit like block</span>

<span style= "FONT-SIZE:24PX;" ></span><pre name= "code" class= "OBJC" >//(num:int)->bool closure parameter type func hascolsurematch (arr:Int[], VALUE:INT,CB: (num:int)->bool) {for    item in arr{        if CB (item) {            return true;        }    }    return false;} var ar = [20,9.100,34,89,39];var v1 = Hasclosurematch (arr,40,{    (num:int), Bool in    return num >= 40;}); println ("V1 is \ (v1)");

The functions of swift and function pointers, closure closure, and other related contents are introduced