Pass by value for primitives

[sandy chauhan]

public class Pass {
       public static void main(String [] args)
	   {
          int x = 5;
          Pass p = new Pass();
          p.doStuff(x);
          System.out.print(" main x = " + x);
       }

      void doStuff(int z) 
	  {
             System.out.print(" doStuff z = " + z++);
      }
 }

The answer for the above code is 5 5

the value of x does not get updated because it has been passed by value

but is there any way to pass a primitive variable by reference???

[Ulf Dittmer]

You can wrap the value into a mutable class, or use an existing class that wraps a mutable integer, like java.util.concurrent.atomic.AtomicInteger. Or have the method return the new value as its result..

[Nitin Mah]

public class Pass {  
    public static void main(String [] args)  
    {  
       //int x = 5;
       
       Pass p = new Pass();
       X x = p.new X(5);
       p.doStuff(x);  
       System.out.print(" main x = " + x.value);  
    }  

   void doStuff(X z)   
   {  
          System.out.print(" doStuff z = " + z.value++);  
   }  
   
   public class X
   {
	   int value;
	   X(int i)
	   {
		   this.value=i;
	   }
   }
}