Show declaration of a Delphi identifier (routine, variable,...)

In Delphi's Code Editor, you can easily jump to the the declaration of an identifier (routine -- procedure or function, variable, constant, type,...). In the source code, right click on the identifier (name of the routine, variable,...) and click on Find Declaration in the popup menu that appears.

For this feature, Delphi must know where the identifier is declared:

1. The declaring unit must be mentioned in a uses clause ( either near the top of the interface section of your unit, or near the top of the implementation section).
   For example, if you are looking for the declaration of the function DaysInAYear then one of the uses clause should include DateUtils, the unit where DaysInAYear is declared:

   unit Unit1;
   interface
   uses
     Windows, Messages, SysUtils, Classes, Graphics, Controls,
     Forms, Dialogs, DateUtils;

2. Delphi must have access to the source code of the unit where the identifier is declared. For identifiers that you declared yourself, that's not a problem, but for the "built-in" identifiers it depends on your version/edition of Delphi. Most Delphi versions have access to these source code files, but not all of the free "Personal" editions do (like for example D7 Personal). Luckily, it works well with the (free) Turbo Delphi Explorer

If you don't know where a certain routine is declared, put the cursor on the routine and press function key F1.
See also: Identifier Declarations.

 Related articles

Built-in identifiers
Where are built-in functions and procedures declared?
ref-identifier-declarations