swift--Closed-Packet expression

Closures, which can be understood as a piece of code enclosed in curly braces.

All of the following belong to the closure

Global functions

Nested functions

Closed-Packet expression

Closure expressions can be used to simplify code and make code more concise

1 varnames = ["Mike","John","Mary","Tom","Bill"]2 3Func Sortfun (s1:string, s2:string)Bool4 {5        returnS1 <S26 }7 8Sort (&names, Sortfun)//sort function A method for ordering after a parameter is used, a method of defining the function form9println (names)//Bill, John, Mary, Mike, Tom .

The following closure expressions are used to simplify

Closure Expressions:

1 /* 2 {3       (parameters)-ReturnType in statements4}5 */

1 //1th Step2 3Sort (&names, {(s1:string,s2:string)-Boolinch returnS1 <S2})4 5 //2nd Step6 7Sort (&names,{(S1,S2), Boolinch returnS1 <S2})8 9 //3rd StepTen  OneSort (&names,{(S1,S2)inch returnS1 <S2}) A  - //4th Step -  theSort (&names,{(S1,S2)inchS1 <S2}) -  - //5th Step -  +Sort (&names,{$0< $1}) -  + //6th Step A  atSort (&names, <)

Can eventually be simplified into sort (&names,<) here Swift except for the < cannot be inferred, other values can be inferred based on what the sort compares.

swift--Closed-Packet expression