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Topic: Object Oriented Concepts (Read 4290 times) |
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ray
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Posts: 6
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Object Oriented Concepts
« on: Nov 14th, 2008, 1:07pm » |
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Suppose you have two classes
!) CassA and ClassB
one way to instantiate ClassB in ClassA is
ClassA {
ClassB b = ClassB();
}
List all other possible ways.
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towr
wu::riddles Moderator
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Re: Object Oriented Concepts
« Reply #1 on: Nov 14th, 2008, 1:41pm » |
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on Nov 14th, 2008, 1:07pm, ray wrote:one way to instantiate ClassB in ClassA is
ClassA {
ClassB b = ClassB();
} |
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Are you quite sure? Instantiating a class in a declaration of a class sounds iffy.
Actually, the real question is, what programming language are you talking about?
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ray
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Posts: 6
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Re: Object Oriented Concepts
« Reply #2 on: Nov 14th, 2008, 2:53pm » |
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well then let it be
ClassA
{
ClassB b=NULL;
public ClassA()
{
b= new ClassB();
}
}
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towr
wu::riddles Moderator
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Re: Object Oriented Concepts
« Reply #3 on: Nov 15th, 2008, 9:51am » |
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Without knowing what programming language you're using I can't tell whether what you do is valid; or provide alternative ways of doing it.
Personally, I would think NULL is an incompatible type with class B; as well as having the same problem as before with instantiating inside a declaration. And further on, you again assign a pointer (which I assume "new" return) to a class that is not a pointer.
But results may vary depending on what programming language you use. Maybe all object are pointers; who knows.
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ray
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Re: Object Oriented Concepts
« Reply #4 on: Nov 15th, 2008, 3:32pm » |
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towr you are really brilliant!! The biggest mistake I made was finding different ways immediately without thinking target language, use.
The way I answered was :
Since it is a has-a relationship (composition), it can be converted to is-a relationship by inheriting classb. Though it may not logically satisfy is-a relationship, but still the derived object will have behavior of classb.
Other way was to use reflection concept in java, c#
eg: classb b = Class.forName("ClassB");
serialization and de-serialization, and using inner classes.
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kvcodes
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Re: Object Oriented Concepts
« Reply #5 on: Aug 29th, 2014, 10:00pm » |
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OOPs concepts are
1)object
2)class
3)encapsulation
4)abstraction
5)polymorphism
6)inheritance
7)message passing
 dynamic binding
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anglia
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Re: Object Oriented Concepts
« Reply #6 on: Aug 11th, 2015, 5:51am » |
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If you wanted to have Class A instantiate ClassB, then you can simply make Class A and call Class B's constructor.
For example:
public class ClassA{
public ClassA()
{
ClassB instance1 = new ClassB();
}
}
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