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Sub class methods

preeti khane
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Joined: Mar 12, 2003
Posts: 93

Answer says 22 according to the exam .. how is that true.. I say the answer is 21
Reshma Shanbhag
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Joined: Sep 17, 2002
Posts: 203
Hi Preeti,

1.
At //Line 1 when u create an instance of Extension, the super class 0 argument constructor is invoked which invokes the add() method with value 1, because of dynamic binding the add() method of Extension is called and not the add() method of Base.

i=0;
i+= 1*2 ;
Therefore the value of i=2;
2.
The constructor of the Child class has an explicit call to add method with value 2. Hence the value of i becomes 6.
i=2;
i += 2*2;
Therefore value of i = 6;
3.
From the method bogo() the add() method is called with a value of 8.

i=6;
i += 8*2;
Therefore value of i = 22;
when called the 'b.print()' method, it calls the method print() inherited by child 'Extension' and hence prints the value of 22.
Hope this clears your doubt
reshma
[ April 02, 2003: Message edited by: Reshma Pai ]

SCJP 1.4, SCWCD 1.4
preeti khane
Ranch Hand

Joined: Mar 12, 2003
Posts: 93
thanks ... As usual I forgot about the dynamic binding call
 
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