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Creating objects in the same class

 
Mukul Anand
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What does it mean to create an object of a class in that same class??
I mean whats the logic??
 
harshvardhan ojha
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In what context are you talking? Where did you found this??
This may be in context of some design pattern, some strategy to take control over constructors or factory methods. Please be specific.
 
Mukul Anand
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well.. sometimes, an object of a class is created within the same class.. Usually, we create an object for a class in another class. Isn't it??
 
harshvardhan ojha
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That depends on your requirement. Lets say i have class A


In both the cases object will be same, only visibility might be different, but that again is valid for access modifiers. The contents of object(i.e. members and variables) will be same.
I mean to say that, object of a class will be same, wherever you create it.
 
Campbell Ritchie
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Are you thinking about singletons? Or factory methods?
 
Jesper de Jong
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Mukul Anand wrote:What does it mean to create an object of a class in that same class??

It doesn't mean anything special; it doesn't matter if you create an instance of a class inside a method of that class, or inside a method of some other class.

Is there a specific scenario that confuses you? If so, then please provide a code example and we can explain what's happening.
 
Mukul Anand
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Nothing specific.. but, I used to believe that an object of a class is and should be made in some other class. So, when I noticed this for the first time, I got confused.
 
Campbell Ritchie
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There can be good reasons why a class creates an instance of itself inside itself. I can think of three reasons offhand (two already mentioned)
  • 1: Singletons
  • 2: Factory methods.
  • 3: Self-referential classes (eg for linked lists).
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    Mukul Anand
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    Okay.. thanks all for your replies
     
    Campbell Ritchie
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    You’re welcome
     
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