C# Property Examples - Dot Net Perls

Make properties with the get and set keywords. Understand that properties are used for data access. HomeSearchC#PropertyExamplesMakepropertieswiththegetandsetkeywords.Understandthatpropertiesareusedfordataaccess.Property.Considerthephysicalcomputeryouareusing.Ithasmanyproperties—asize,aweight,adateitwasbuilt.Propertiesdescribethiscomputer.Propertyuse.InC#,weusepropertiesonaclass(likeaComputerclass)todescribetheclass.Theycanbesetandreadfromlikeotherfields,andspecialcodecanberun.Simpleexample.Tostart,weintroduceanExampleclass.Onefield,aninteger,ispresent—itisusedasabackingstorefortheNumberproperty.NumberThisisanintpropertyintheExampleclass.Numberprovidesgetandsetimplementations.GetThegetimplementationmustincludeareturnstatement.Itcanaccessanymemberontheclass.SetThesetimplementationreceivestheimplicitargument"value."Thisisthevaluetowhichthepropertyisassigned.ValueC#programthatusespublicintpropertyusingSystem; classExample { int_number; publicintNumber { get { returnthis._number; } set { this._number=value; } } } classProgram { staticvoidMain() { Exampleexample=newExample(); example.Number=5;//set{} Console.WriteLine(example.Number);//get{} } }5Automaticproperty.WeseeautomaticallyimplementedpropertysyntaxinC#.Ahiddenfieldisgenerated—thenthegetandsetstatementsareexpandedtousethathiddenfield.ExpressionThe*=operatorisusedtomultiplythepropertybyitself.Becausepropertiesaremeanttolooklikefields,thisisallowed.C#programthatusesautomaticallyimplementedpropertyusingSystem; classExample { publicintNumber { get; set; } } classProgram { staticvoidMain() { Exampleexample=newExample(); example.Number=8; example.Number*=4; Console.WriteLine(example.Number); } }32Enum.ThisexampleshowstheDayOfWeekenumtypeinaproperty.Wealsoinsertcodeinthegetter(orsetter)thatchecksthebackingstoreortheparametervalue.EnumDayOfWeekTypesLikeamethod,apropertycanactonanytype,evenenumtypeslikeDayOfWeek.Manypropertieswillusestringorint.C#programthatusesenumpropertyusingSystem; classExample { DayOfWeek_day; publicDayOfWeekDay { get { //Wedon'tallowthistobeusedonFriday. if(this._day==DayOfWeek.Friday) { thrownewException("Invalidaccess"); } returnthis._day; } set { this._day=value; } } } classProgram { staticvoidMain() { Exampleexample=newExample(); example.Day=DayOfWeek.Monday; Console.WriteLine(example.Day==DayOfWeek.Monday); } }TruePrivate.Wemakeaprivateproperty.HeretheIsFoundpropertycanonlybesetintheExampleclass.WesetitintheExampleconstructor.ThenWecanonlygetthepropertyintheProgram.MainmethodbyusinganExampleinstance.C#programthatusesprivatesetterinpropertyusingSystem; classExample { publicExample() { //Settheprivateproperty. this.IsFound=true; } bool_found; publicboolIsFound { get { returnthis._found; } privateset { //Canonlybecalledinthisclass. this._found=value; } } } classProgram { staticvoidMain() { Exampleexample=newExample(); Console.WriteLine(example.IsFound); } }TrueEntireproperty.Wecanalsomakeanentirepropertyprivate.Ifwedothis,wecanonlyusethepropertyinthesameenclosingclass.PrivateTheDisplaymethodintheexampleshowshowtousetheprivateproperty.NoteThissyntaxislessusefulinmostprograms.Butitexists,andmaybehelpfulinacomplexclass.ClassC#programthatusesprivatepropertyusingSystem; classExample { int_id; privateintId { get { returnthis._id; } set { this._id=value; } } publicvoidDisplay() { //Accesstheprivatepropertyinthismethod. this.Id=7; Console.WriteLine(this.Id); } } classProgram { staticvoidMain() { Exampleexample=newExample(); example.Display(); } }7Static.Propertiescanalsobestatic—thismeanstheyareassociatedwiththetypeandnotaninstance.Staticclassescanonlyhavestaticproperties.StaticCountThispropertyhasasideeffect.Itcausesthefieldtobeincrementeduponeachaccess.WarningSideeffectsarenotusuallyagooddesignfeatureinprograms.Theycanmakethelogichardtofollow.SetterThisisomitted.Thismakessenseforapropertythatcomputesavalueentirelyinmemory,orbasedonotherfieldsorproperties.C#programthatusesstaticpropertyusingSystem; classExample { staticint_count; publicstaticintCount { get { //Sideeffectofthisproperty. _count++; return_count; } } } classProgram { staticvoidMain() { Console.WriteLine(Example.Count); Console.WriteLine(Example.Count); Console.WriteLine(Example.Count); } }1 2 3Automatic,private.Letusconsiderhowtomakegettersorsettersonanautomaticproperty.Wecannotomiteitherthegetterorsetterinthiskindofproperty.NoteTheerrorreportedbytheC#compilerreads:"Automaticallyimplementedpropertiesmustdefinebothgetandsetaccessors."C#programthatusesprivatesetter,autopropertyusingSystem; classExample { publicExample() { //Useprivatesetterintheconstructor. this.Id=newRandom().Next(); } publicintId { get; privateset; } } classProgram { staticvoidMain() { Exampleexample=newExample(); Console.WriteLine(example.Id); } }2077325073Automatic,defaultvalues.Automaticpropertieshavesupportfordefaultvaluesmuchlikefields.HereweassigntheQuantitypropertyofMedicationto30bydefault.C#programthatusesdefaultvalueusingSystem; classMedication { publicintQuantity{get;set;}=30;//Hasdefaultvalue. } classProgram { staticvoidMain() { Medicationmed=newMedication(); //Thequantityisbydefault30. Console.WriteLine(med.Quantity); //Wecanchangethequantity. med.Quantity*=2; Console.WriteLine(med.Quantity); } }30 60Expression-bodiedproperties.Wecanuselambda-stylesyntaxtospecifyproperties.Theseareexpression-bodiedproperties—weuse"get"and"set"andthentheresultontherightside.C#programthatusesexpression-bodiedpropertiesclassProgram { privatestaticinttest; publicstaticintTest{get=>test;set=>test=value;} staticvoidMain() { //Usetheproperty. Program.Test=200; System.Console.WriteLine(Program.Test); } }200Benchmark,properties.Compileroptimizationsensurethatpropertiesareefficient.Thesesameoptimizationsareusedonmethods,whichsharetheunderlyingimplementationwithproperties.Version1Thiscodeusesaproperty.Itsetsaproperty,andthengetsthevalueoftheproperty.Version2Thisversionofthecodeusesafielddirectly.Itperformsthesamelogicalstepsthatversion1does.ResultTherewasnodifferenceinperformancewiththepropertyandthefield.Itisapparentthepropertyaccessisinlined.TipTheJITcompilercaninlinepropertiesthatdon'thavelogicinsideofthem.Sotheyareasefficientasfields.C#programthatbenchmarkspropertiesusingSystem; usingSystem.Diagnostics; classProgram { staticstring_backing;//Backingstoreforproperty. staticstringProperty//Getterandsetter. { get { return_backing; } set { _backing=value; } } staticstringField;//Staticfield. staticvoidMain() { constintm=100000000; for(intx=0;x<10;x++)//Tentests. { Stopwatchs1=newStopwatch(); s1.Start(); //Version1:testproperty. for(inti=0;i