Objects accessing each other

[Vikash Agarwal]

Ques: Can one object can access a private variable of another object of the same class?
Ans: YES. Private means "private to the class", NOT "private to the object". So two objects of the same class could access each other's private data.

I want to understand (with an example probably) how.
Please can someone help.

[Leandro Melo]

Hi.

This example might help you:

//In file Test.java.
public class Test
{ 
  public static void main(String[] args)
  {
    SomeClass obj1 = new SomeClass();
    SomeClass obj2 = new SomeClass();
    obj1.setPrivateInteger(10);
    obj2.accessPrivateInteger(obj1);
  }   
}
 
class SomeClass
{
  private int privateInteger;
  
  public void setPrivateInteger(int newvalue)
  {
    this.privateInteger = newvalue;
  }  
  
  public void accessPrivateInteger(SomeClass other)
  {
    System.out.println("Private integer of other: " + other.privateInteger);
  }
}

[ June 05, 2007: Message edited by: Leandro Melo ]

[Stan James]

Take a quick look at the Comparable interface and the compareTo method. This asks an object to compare itself to another object, usually another instance of the same class. It often winds up like this:

public int compareTo( Object o )
{
   ThisClass other = (ThisClass)o; // assume same class
   int result = this.field1.compareTo( other.field1 );
   ... maybe compare more fields ...
   return result;
}

If "field1" is private, we need to access the private field of the "other" instance. And Java lets us.

[Vikash Agarwal]

impressive... thanks buddies !!!

[Raghavan Muthu]

Its an interesting topic .. thanks for posting it vikas and thanks to Leandro Melo and Stan James for the good example.

Is it more or less resembling like the Copy Constructor in C++. Aint I?