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Java Java Data Structures - Retired Organizing Data Interfaces

Majed Nabil
Majed Nabil
2,180 Points
Posted by Majed Nabil
Majed Nabil
2,180 Points

about casting

I have a question, when Mr.Craig casts the obj, I do not know where is the obj defined in the program, can anyone help in this?

1 Answer

Sławomir Lasik
Sławomir Lasik
7,792 Points
Sławomir Lasik
Sławomir Lasik
7,792 Points

Well, it isn't Not now anyway... In the compareTo(...) method you only know that you, other programmer, or for example sorting program (which sorts the Treet objects) will try to compare Treet object to other Object which should be Treet. (It is pointless to call treet.compareTo(SomeString) isnt't ? it will fail anyway). You and others should do that with compareTo(...) method. How? You call the compareTo(...) method on the Treet object giving the other object that You want to compare to. You, other programmer, sorting program should call the compareTo(...) method giving the other Treet object that You want to campare to.

In the example shown by the Proffesor, you see, that compareTo() method is needed by the sorting algorythm. That's when this method is called and the Treet object is passed.