DelphiBasics TObject Type The base class type that is ancestor to all other classes System unit

type TObject = class   constructor Create;   ...   ...   destructor Destroy; virtual;  end;

Description The TObject type defines the base class type. It is the oldest grandparent of all classes - every class is ultimately derived from TObject.   Because of this, every object inherits the methods of TObject.   The TObject methods fall into two categories - class and non-class. When prefixed by the keyword Class, a method may be called in both an object of the class, and in the class itself. Such a static method cannot access any class fields because a class has no data itself - only instantiated classes - objects - have data.   Some key Class (static) methods:   function ClassName  Gives the class name as a string ClassParent  Gives the class parent name ClassInfo  Gives class Run Time info InstanceSize  Size of class object in bytes NewInstance  Creates a new class object   Some key Object methods:   Create  Empty object creator Free  Calls Destroy for a non-nil object ref Destroy  Releases object storage AfterConstruction  Called after construction BeforeDestruction  Called before destruction Related commands Class Starts the declaration of a type of object class Printer Returns a reference to the global Printer object  Download this web site as a Windows program.

Example code : Using TObject methods inherited in a TForm subclass begin   // The unit form was derived from TObject.   // So we can use methods of TObject:   ShowMessage('Form1 object class name = '+               Form1.ClassName);   ShowMessage('Form1 object class parent name = '+               Form1.ClassParent.ClassName);   ShowMessage('Form1 object instance size = '+               IntToStr(Form1.InstanceSize));   // And now on TObject itself   ShowMessage('TObject class name = '+               TObject.ClassName);   ShowMessage('TObject instance size = '+               IntToStr(TObject.InstanceSize)); end; Show full unit code   Form1 object class name = TForm1   Form1 object parent class name = TForm   Form1 object instance size = 764   TObject class name = TObject   TObject instance size = 4

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