is this an aliasing ?

[Dan D'amico]

public class Disco
{
   LightBulb bulb1;

  //constructor
   public Disco(LightBulb b1){
	bulb1 = new LightBulb(b1);  // thats not aliasing i know. 
   }

   //getter
   public LightBulb getFirstBulb(){
	return bulb1; // this is aliasing ? instead should i write return new LightBulb(bulb1) ? if so , why ?

   }
}

[Harish Shivaraj]

 public Disco(LightBulb b1){  
    bulb1 = new LightBulb(b1);  // thats not aliasing i know.   
   }  
  
   //getter  
   public LightBulb getFirstBulb(){  
    return bulb1; // this is aliasing ? instead should i write return new LightBulb(bulb1) ? if so , why ?  
  
   }  

Aliasing is when you have more than one reference to an object. For instance

Shape s1 = new Rectangle( 10, 20 );
Shape s2 = s1;

You see with the above snippet object Rectangle has two reference through s1 and s2 precisely. Translating this to you code. The getFirstBuild is intended to return a reference to the object bulb1 instead of returning "new LightBulb(bulb1)". Latter would indeed create you new object. Which you certainly not intending to want.

If your after multiple references to the object bulb1 you just need to return bulb1 and assign that to new bulb2 of type LightBulb.

[Dan D'amico]

thanks. i undetstood !