iOS two development (SWIFT) enumeration

//: Playground-noun:a Place where people can playImport UIKit//Raw Valueenummonth:string{ CaseJanuary ="value_january"     CaseFebruary ="value_february"     CaseMarch ="Value_march"     CaseApril ="Value_april"     CaseMay ="Value_may"     CaseJune ="Value_june"     CaseJuly ="value_july"     CaseAugust ="Value_august"     CaseSeptember ="Value_september"     CaseOctober ="Value_october"     CaseNovember ="Value_november"     CaseDecember ="Value_december"}func season (Month:month)-string{SwitchMonth { Case . January:returnMonth.rawvaluedefault:        return ""}}season (month:Month.January) print (Month.april)ifLet July = Month (rawValue:"value_july") {print (July)}//Associate Value//Example 1enumatmstatus{ CaseSuccess (Int) CaseError (String) CaseWaiting}var Balance= +func Withdraw (amount:int)-atmstatus{ifAmount <=Balance {Balance-=Amountreturn . Success (Balance)}Else {        return. Error ("Not enough money")}}let result= Withdraw (Amount: -)SwitchResult { CaseLet . Success (newbalance): Print ("\ (newbalance) Yuan left on your account.")     CaseLet . Error (errormessage): Print ("error:\ (errormessage)")     Case . Waiting:print ("Waiting")}SwitchResult { Case . Success:print ("Success")     Case . Error:print ("Error")     Case . Waiting:print ("Waiting")}//Example 2enumshape{ CaseSquare (side:double) CaseRectangle (width:double, height:double) CaseCircle (centerx:double, centery:double, radius:double) CasePoint}let Square= Shape.square (side:Ten) Let Rectangle= Shape.rectangle (width: -, Height: -) Let Circle= Shape.circle (CenterX:0, CenterY:0, Radius: the) Let point=Shape.pointfunc Area (shape:shape)-double{SwitchShape { CaseLet . Square (side):returnSide *side CaseLet . Rectangle (width, height):returnWidth *Height CaseLet . Circle (_, _, R):returnM_PI * R *R Case . Point:return 0}}area (shape:square) area (shape:rectangle) area (shape:circle) area (shape:point)

iOS two development (SWIFT) enumeration