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Very Interesting question!!!!!

 
Greenhorn
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Hi All!!

while working on one of topic posted in the forum..i end up with very tricky question...here it is..

what will be the output of the below program!!!

 
Ranch Hand
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I think- "HarMol","uk","uk"
 
kamal shah
Greenhorn
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No.......Just copy this program and run this on your machine you will find something very interesting!!!
 
Nadeem Khan
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Ya you are right! its "HarMol", "uk", "dub"!
Ok i got it, here jume() is called on refernce "hs" which updates its objects's "nat" from "dub" to "uk" value. Hence hs.nat shows "uk".

But "this" refers to the "hm" which originally called go() and hence its showing its nat (this.nat) as the initial value "dub"
 
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what would be the o/P??
 
Greenhorn
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The O/p is :

HarMol
uk
dub
 
Ranch Hand
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I didnt get it

Firstly I thought there would be compile time error for "nat=UK" as
I thought that's behaving like a local variable which is not declared (ie String).

Can someone explain in detail what's happening there..and what's being updated and how.
 
Deepak Kumar
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do not consider the commented lines.
 
Deepak Kumar
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consider the below code.



what is the o/p?
 
Greenhorn
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Hi

I couldn't get how the value of "this.nat" is "dub" ....

please elaborate on this some more...

Thanks in advance...

Varsha
 
Nabila Mohammad
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I thought it would be

HarMol
uk123
uk123

But the output is
HarMol
dub
uk123

How does inheritance influence the instant variable?
Does the child class replace it with a new value or are they separate variables.

Also if we are creating a child class object with the reference of the Parent class ,why is it acessing the parent class variable,
unlike (overriding) method which will execute the child class method.
 
Greenhorn
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Hi Nabila,

Instance variables are inherited but they are not polymorphic. Polymorphic invocations are only for overridden instance methods. Not for variables, not for static methods.
This is explained in K&B, Chapt 2. Polymorphism, last para.

So since HelSte hs is a reference to parent type,
hs.nat will be dub.

this.nat be uk123 since 'this' is hm.

If you say
HarMol hs = new HarMol();
hs.nat will be uk123

Hope this helps,
Sheryl.
 
Nabila Mohammad
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Thanks.That helps alot.
 
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