Doubt about java Class

[leela krishhna]

How to find the Number of objects that are created for a particular class...

Mention any referral example code....

[fred rosenberger]

Why do you think you can or should be able to do this?

[Kemal Sokolovic]

If you want to know how many instances of the class you defined are created, you can accomplish it by adding a static field to your class definition and increment it each time an instance is created.
Though, I can't really see a good point of doing it...

[leela krishhna]

How increase that static value every time of creating objest..

Please give the code for it...

[Eswar Nec]

Hi,

First you learn use of static varible..After that you can understand 'Kemal Sokolovic' answer.

Before ask question, you need to refer some example in some sites.
I sent some tips you. See your private message.

[Kemal Sokolovic]

leela krishhna wrote:How increase that static value every time of creating objest..

Ple\ase give the code for it...

I suppose you've already heard of static variables, and know how to use them. If not, I would suggest you go and read about it a little, so you might get an idea what I was talking about.
Anyway, key words are - every time you CREATE an object. Any idea now?

[Raza Mohd]

Its Like a Puzzle solving session . Did you get the hint leela?

[harshvardhan ojha]

increment static variable inside constructor.

[narayana Ega]

declare a static variable inside of your class constructor and make sure that it is increasing its value by 1 for every call of that constructor....

while processing you may destroy some objects for that in finalize() decrease that static variable...

then you will get the count of active instances............

[leela krishhna]

Finding no.of Objects created for a class...
I finally got this code...
Any modifications, please suggest

public class Demo
{
    public static int count=0;
    //Intance block
      {
         count++; 
      }
    //Constructors
    Demo(){  }
    Demo(int x){}  
    Demo(int x,float y){  }  
    Demo(int x,int y,int z){  }
    Demo(int x,int y,int z,float p){   }   
 
  public static void main(String args[])
  {
    Demo t1=new Demo();
    Demo t2=new Demo(1,2.5f);
    Demo t3=new Demo(4);
    new Demo();
    Demo t4=new Demo();
    Demo t5=new Demo(5,6,7);
    Demo t6=new Demo(5,6,7,6.8f);
       
    System.out.println("The Number of Objects created for class is = "+Demo.count);
  }
}

[Campbell Ritchie]

That might get you the number of instances created, but you do not know whether any have gone out of scope or been garbage collected.
It will also get you 0 out of 10 for good object‑oriented design. That count variable might be modified outside your Demo class, and you would never know about it.

[Paul Clapham]

Campbell Ritchie wrote:That might get you the number of instances created, but you do not know whether any have gone out of scope or been garbage collected.

True, but we don't need to know that. The original question was

How to find the Number of objects that are created for a particular class

[Kemal Sokolovic]

leela krishhna wrote:Finding no.of Objects created for a class...
I finally got this code...
Any modifications, please suggest

public class Demo
{
    public static int count=0;
    //Intance block
      {
         count++; 
      }
    //Constructors
    Demo(){  }
    Demo(int x){}  
    Demo(int x,float y){  }  
    Demo(int x,int y,int z){  }
    Demo(int x,int y,int z,float p){   }   
 
  public static void main(String args[])
  {
    Demo t1=new Demo();
    Demo t2=new Demo(1,2.5f);
    Demo t3=new Demo(4);
    new Demo();
    Demo t4=new Demo();
    Demo t5=new Demo(5,6,7);
    Demo t6=new Demo(5,6,7,6.8f);
       
    System.out.println("The Number of Objects created for class is = "+Demo.count);
  }
}

This seems ok for what you were looking. I would just modify class a little bit, by setting count to be private, and provide just one getter for reading it's value.

[Ivan Jozsef Balazs]

A sidenote: with multithreading (i.e. concurrently creating several instances) the counter might become inaccurate.