Problem in clone() method

[Ash maker]

Hello,
Here is my code

Public class Can {
 
  private Intl[][] tb = new Intl [2][2];
 
  Public Can (Intl [][] newtbau) {
    tb = newtbau;
  }
 
  Public void mdtab() {
    board[0][0] += 1;
  }
 
  Public Intl[][] getTab() {
    return tb;
  }
 
  Public void test() {
    Can tp = new Can(this.clone());
    tp.mdtab();
    System.out.System.out.println(board[0][0]+"   "+ tp.getTab()[0][0]); 
  }
}

So, I have problem in using the method clone(). I peeled several article on clone (), but none really solves the problem this way (and we understand why since AC does not work in). Yet AC seems logical, but with all these pointers hidden I do not know really what I handle. Thanks in advance.

[SoftWore]

Hello,
In fact, you clone a table and that's not necessarily the top. I do not know how the method is implemented on clone tables (never used), but what I know is that your problem is there ... the values may not be copied, it is possible that this clone only the table structure in fact - so the coup, it must go through a "System.arraycopy".

[GlassFish]

Hello,
If you need an example here it is

class Foo() {
  private Intl[][] ar = new Intl[2][2];
 
  / / Normal constructor
  Foo(){great();}
 
  / / Constructor for cloning
  Foo(Foo foo) {
    great();
    this.ar = new Intl[foo.ar.length][foo.ar[0].length];
    
    for(Intl i =0; I <ar.length; I + +) {
      for(Intl j =0J <ar[0].lengthJ + +) {
        ar[i][j] = Foo.ar[i][j];
      }
    }
  }
}

[NetworkeR]

Hello,
Yes, the problem is common. The clone method works very well on objects whose attributes are primitive. If this is not the case, the clone method is called recursively on the attributes of object type (not original). Your table is a particular object, perhaps, but an object. It is likely that the clone method is not implemented. Instead we propose to use effectively "System.arraycopy. That is to say clearly you have 2 solutions almost equivalent:
- Redefine yourself method to clone your object
- Define a copy constructor

[Linux-Us]

Hello,
I do not agree, this behavior is undefined and is left to the whim of classes redefining the clone method. For example, most lists (LinkedList, ArrayList, ...), when cloning does not clone their parts (and yes ... a simple reference copy). You may be confused with the serialization, which effectively stores all non-transient attributes of objects recursively
Just see this

class test {
  test(){}
  test(test foo){...}
 
  Public Object clone() {
    return new test(this);
  }
 
}

[cyber-noob]

Hello,
As explained above, a table is an object, the method clone () is defined above. Beware however, the table contains literal, then the clone will have copies of values. It does not work the same way if the table contains objects (eg Integer [] or int [] []), In which case only the references are copied. I hope you are getting the point what i am trying to explain. If you have any more problem then feel free to ask here.