Array of objects

Or:

SevenSegmentExtended dispArray[] = {
  {Disp1Ck, Disp1Io}, 
  {Disp2Ck, Disp2Io},
  {Disp3Ck, Disp3Io},
  {Disp4Ck, Disp4Io}
};

dispArray[1].print("yay");

Pieter