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having problems understanding polymorphism combinations  RSS feed

 
alex lotel
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if i have food class and pie class which inherits food
regarding the accsess level

i have


i know that both are reference variable of pie,
but x is of type pie and y is of type food.
what is the difference between the two regarding method accsess in both classes
?
 
Jeff Verdegan
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donaldth smithts wrote:if i have food class and pie class which inherits food


Food and Pie. By convention, Java class names start with uppercase letters.

i have


"I have." By the rules of English grammar, the personal pronoun "I" is always capitalized. If you UseRealWords(⇐click) it makes it easier to read and understand your question.



i know that both are reference variable of pie,


No. The "x" variable is of type reference-to-Pie, and the "y" variable is of type reference-to-Food.


what is the difference between the two regarding method accsess in both classes
?


What do you mean?
 
alex lotel
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so if in both classes i have a (non static) mathod "eat"
and will do

x will call the method from pie
and y will call the method from pie.

question regarding case 1:
if "food" doesnt have a method "eat"

what will happen?

and on the opposite case 2:
if "food" has a method "eat" but pie doesnt ave one

what will happen?

and the same as case 2

what will happen?
 
John Jai
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donaldth smithts wrote:what is the difference between the two regarding method accsess in both classes?

x can call all the methods defined in pie and y can call only the inherited methods of food in pie.
 
alex lotel
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so "y" can use only the methods in pie which are present in food
correct?
 
John Jai
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donaldth smithts wrote:question regarding case 1:
if "food" doesnt have a method "eat"

what will happen?

It won't compile because there is no eat() method defined for the type food.
donaldth smithts wrote:
and on the opposite case 2:
if "food" has a method "eat" but pie doesnt ave one

what will happen?
and the same as case 2

what will happen?

The eat() method in food will be called since pie inherits the method eat() method from its super class food.

This thread might interest you.
 
John Jai
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donaldth smithts wrote:so "y" can use only the methods in pie which are present in food
correct?

methods in inherited in pie. Say if a final method is present in food which will not be present in pie, but inherited by pie.
 
Jeff Verdegan
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donaldth smithts wrote:so if in both classes i have a (non static) mathod "eat"
and will do


Why don't you try it and see?

And please, have the common courtesy to write proper English. Thanks!
 
alex lotel
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i am not native english speaker so please be considerate

So to summerise my cases:



regarding x.eat():
if there no eat method in pie 'but there is one in food then it will call the method from food because it inherits food class.
if there is eat in pie then it will call the method from pie.

regarding y.eat():
if there is no eat method in food then it wont compile because y is of type food.
if there is no eat in pie but there is one in food then it will call the method eat in food.

correct?

 
Joanne Neal
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donaldth smithts wrote:correct?


As long as the access modifiers of each of the methods allows access, yes.
 
Jeff Verdegan
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donaldth smithts wrote:i am not native english speaker so please be considerate


I am being considerate. I'm simply asking you to do the same.

Even though you are not a native speaker, I'm sure you learned the basics of capitalization and punctuation. I don't expect your grammar to be perfect, but it is fair to expect you to try. I politely asked you to make an effort to write correctly, briefly told you why, and provided a link with more information. You do not seem to be making an effort however, so I will bow out now and let others help you.

Good luck.
 
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