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equals()

 
Bob Tank
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Question:
Which of these statements are true?
A. If the references x and y denote two different objects, then the experssion x.equals(y) is always false.
B. All array objects have a method named clone.
Answer is B only. Why isn't answer A. true???
Thanks
 
Noah Carroll
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x.equals(y); could be false because the equals() method tests the value of the object not the reference.
however, i don't think it would always be false, because if both objects have the same values then it would be true.
 
Marilyn de Queiroz
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For instance:
String String1 = "abc";
String String2 = "abc";
String1.equals(String2) returns true.
Marilyn
 
Anonymous
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Marilyn,
While your answer is technically correct, I feel it is not the right example in this case because String1==String2will return true also.
Ambrose
 
Ajith Kallambella
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Bob,
The equals method is defined in the Object class and it does nothing but basic reference comparison. Several subclasses of Object override the equals method to do content based comparison. The examples are the wrapper classes and the String class.
However, there are some derivatives of Object that doesnot override the equals method. One such class is the StringBuffer. If a class (derived from Object ) does not override the equalsmethod, then as per the OO rules, calling equals method on an instance of such a class will call the Object.equals() method.... and you know what happens
Hence the answer A is false!
Hope that helps,
Ajith
[This message has been edited by Ajith Kallambella (edited October 10, 2000).]
 
Subramaniam Chidambaram
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Hi,
If i understand correctly.
If the equals() method is not overridden then the objects
equals() method is called which is same as ==
Thanks

------------------
Subbu
 
Marilyn de Queiroz
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Yes, Subbu, that is true.
Marilyn
 
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