Passing by value vs pass by reference

Argument Passing
When a simple type is passed to a method, it is done by use of call-by-value. Objects are passed by use of call-by-reference.
So when object is passed,  it is passed as reference.

Returning objects
Let Test be a class, and

class Test {
    int a;
      Test(int i) {          a = i;
       }
   Test increase {
    Test temp = new Test(a+10);
    return temp;
  }
}


As you can see, each time increase( ) is invoked, a new object is created, and a
reference to it is returned to the calling routine.
The preceding program makes another important point: Since all objects are
dynamically allocated using new, you don’t need to worry about an object going
out-of-scope because the method in which it was created terminates. The object will
continue to exist as long as there is a reference to it somewhere in your program.
When there are no references to it, the object will be reclaimed the next time garbage
collection takes place.
Java supports recursion.