Why we need a struct? When to use it?

i'm rookie in c#, was reading demo projects recently , found modle class, , don't konw why need struct, it seems same class. difference them? why need use struct?

hello,

main difference structs passed\copied value , classes passed\copied reference

i wrote demo illustrate statement. please have look

here "pointclass"

class pointclass     {                    public int x,y;             public pointclass(int x,int y)             {                 this.x = x;                 this.y = y;             }     }

in main class

 class program     {         public struct pointstruct         {             public int x,y;             public pointstruct(int x, int y)             {                 this.x = x;                 this.y = y;             }         }         static void main(string[] args)         {             pointstruct structpoint = new pointstruct();             structpoint.x = 10;             structpoint.y = 10;              console.writeline("initial struct value " + structpoint.x + "," + structpoint.y);             modifystructpoint(structpoint);             console.writeline("after modifystructpoint,struct value  " + structpoint.x + "," + structpoint.y);              pointclass classpoint = new pointclass(10,10);             console.writeline("initial class value " + classpoint.x + "," + classpoint.y);             modifyclasspoint(classpoint);             console.writeline("after modifyclasspoint,class value  " + classpoint.x + "," + classpoint.y);             console.read();         }          static void modifystructpoint(pointstruct mystruct)         {              mystruct.x = 20;             mystruct.y = 20;             console.writeline("inside modifystructpoint()");             console.writeline("struct after modify " + mystruct.x +","+ mystruct.y);         }           static void modifyclasspoint(pointclass myclass)         {              myclass.x = 20;             myclass.y = 20;             console.writeline("inside modifyclasspoint()");             console.writeline("class after modify " + myclass.x + "," + myclass.y);         }     }

after execute program, shows below

have nice day!

kristin

Visual Studio Languages  ,  .NET Framework  >  Visual C#