Difference between revisions of "Class"
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A highly structured data [[type]] in Object [[Pascal]] dialects such as Delphi or the [[ObjFPC]] dialect. Classes are able to contain [[variable]]s, [[constructor]]s, [[destructor]]s, [[function]]s, [[procedure]]s, and properties using access scopes. Another interesting thing about classes is that they free the programmer from the need for [[pointer]]s and [[reference]]s. They are automatically handled by the [[compiler]] at compile time. Classes are able to inherit and to be inherited by other classes. | A highly structured data [[type]] in Object [[Pascal]] dialects such as Delphi or the [[ObjFPC]] dialect. Classes are able to contain [[variable]]s, [[constructor]]s, [[destructor]]s, [[function]]s, [[procedure]]s, and properties using access scopes. Another interesting thing about classes is that they free the programmer from the need for [[pointer]]s and [[reference]]s. They are automatically handled by the [[compiler]] at compile time. Classes are able to inherit and to be inherited by other classes. | ||
| + | |||
| + | <delphi> | ||
| + | type | ||
| + | TMyClass = class(TObject) | ||
| + | private // self access only | ||
| + | FSomeVar: Integer; | ||
| + | public // access by anything | ||
| + | constructor Create; overload; | ||
| + | constructor Create(Args: array of Integer); overload; | ||
| + | destructor Destroy; virtual; | ||
| + | function GetSomeVar; | ||
| + | procedure SetSomeVar(newvalue: Integer); | ||
| + | published // special type of public scope | ||
| + | property SomeVar: Integer read GetSomeVar write SetSomeVar default 0; | ||
| + | end; | ||
| + | </delphi> | ||
| + | |||
| + | <delphi> | ||
| + | var | ||
| + | classInstance: TMyClass.Create; | ||
| + | </delphi> | ||
| + | |||
| + | <delphi> | ||
| + | TMyClass.Create; | ||
| + | begin | ||
| + | SomeVar := 6 | ||
| + | end; | ||
| + | </delphi> | ||
Revision as of 05:06, 30 March 2009
A highly structured data type in Object Pascal dialects such as Delphi or the ObjFPC dialect. Classes are able to contain variables, constructors, destructors, functions, procedures, and properties using access scopes. Another interesting thing about classes is that they free the programmer from the need for pointers and references. They are automatically handled by the compiler at compile time. Classes are able to inherit and to be inherited by other classes.
<delphi> type
TMyClass = class(TObject)
private // self access only
FSomeVar: Integer;
public // access by anything
constructor Create; overload;
constructor Create(Args: array of Integer); overload;
destructor Destroy; virtual;
function GetSomeVar;
procedure SetSomeVar(newvalue: Integer);
published // special type of public scope
property SomeVar: Integer read GetSomeVar write SetSomeVar default 0;
end;
</delphi>
<delphi> var
classInstance: TMyClass.Create;
</delphi>
<delphi> TMyClass.Create; begin
SomeVar := 6
end; </delphi>
