somDescendedFrom

This method tests whether one class is derived from another. Not generally overridden.

For backward compatibility, this method does not take an Environment parameter.

Original Class: SOMClass

Syntax

boolean somDescendedFrom (SOMClass receiver, SOMClass aClassObj)

Parameters

receiver (SOMClass): A pointer to the class object to be tested.
aClassObj (SOMClass): A pointer to the potential ancestor class.

Return Code

rc (boolean)

Returns 1 (true) if receiver is derived from aClassObj. 0
Returns 0 (false) if receiver is not derived from aClassObj.

Remarks

This method tests whether the receiver class is derived from a given class. For programs that use classes as types, this method can be used to ascertain whether the type of one object is a subtype of another.

This method considers a class object to be descended from itself.

Example Code

#include <dog.h>
/* --------------------------------------------
   Note: Dog is a subclass of Animal.
   -------------------------------------------- */
main()
{
  AnimalNewClass(0,0);
  DogNewClass(0,0);

  if (_somDescendedFrom (_Dog, _Animal))
     somPrintf("Dog IS descended from Animal\n");
  else
      somPrintf("Dog is NOT descended from Animal\n");
  if (_somDescendedFrom (_Animal, _Dog))
     somPrintf("Animal IS descended from Dog\n");
  else
     somPrintf("Animal is NOT descended from Dog\n");

This program produces the following output:

Dog IS descended from Animal
Animal is NOT descended from Dog