Delphi declares its own class and its calling method

{Type is placed below the uses reference unit under interface }
1 //declaring classes2 type3Tmyclass =class                               //Note that this cannot be added '; ' because it's a whole.4Data:integer;//domain of the class5     procedureChangedata (Value:integer);//class Method (procedure) press CTRL + SHIFT + C key to automatically generate function body6     functionGetdata:integer;//method of the Class (function)7     //The fields and methods of the class can be added according to your needs8 End;9 Ten {Tmyclass} One procedureTmyclass.changedata (Value:integer); A begin -Data: = Value;// - End; the  - functionTMyclass.GetData:integer; - begin -Result: =Data; + End; -  + //Access Class A procedureTform1.speedbutton2click (sender:tobject); at var - Myclass:tmyclass; - I:integer; - begin -   Try -MyClass: = Tmyclass.Create;//must be instantiated before use, otherwise it will not be used inMyClass. Changedata ( A);//assigns a value to the method of the class, -I: = MyClass. GetData;//gets the class toShowMessage (IntToStr (i));//{A} +   finally -MyClass. Free;//Finally, you need to release the used memory the   End; * End;

In addition, there are two special methods in the class, the method (Constructor) and the Destructor method (destructor) are constructed respectively.
A class is an object-oriented idea.

Delphi declares its own class and its calling method