POLYMORPHISM

• POLYMORPHISM: SAME OPERATION CORRESPONDS TO DIFFERENT METHODS (IMPLEMENTATIONS) DEPENDING ON OBJECT TYPE
  
  
  • EXAMPLE: DISPLAY POLYGON; DISPLAY PIE CHART, ETC..
  
  
• IMPLEMENTATION OF OPERATION IS REDEFINED FOR EACH SUBCLASS: OVERRIDING
  
  
  • SINGLE OPERATION NAME DENOTES DIFFERENT METHODS
  
  
• SYSTEM DECIDES WHICH METHOD TO USE:
  
  
  • OBJECT TYPE KNOWN AT COMPILE TIME (STRONGLY TYPED): COMPILER SELECTS METHOD
  • OBJECT TYPE KNOWN AT RUN-TIME: DELAYED BINDING TO RUN-TIME: LATE BINDING
    
    
    • TYPICAL CASE
    
    
  
  

Previous: Page 19 Next: Page 21 Up A Level: TOC

Ugo O. Gagliardi
GSD-6306 Spring 2003-2004