Strings and Object References in Java

The String class is used for text manipulation. As you read, you will learn different ways to create Strings, methods to manipulate Strings, the String concatenation operator '+', and about how Strings are immutable.

8. Not Garbage



Answer:
String alpha =  new String("Red Rose");
String beta  = alpha;
alpha = null;
  1. When was an object instantiated?       In the first statement.
  2. What happens in the second statement?       The reference to the object is copied to beta.
  3. What becomes of that object?       It remains "alive," because there is still a reference to it.


Not Garbage


notGarbage








    
This time, the object does not become garbage. This is because in the second statement a reference to the object is saved in a second variable, beta. Now when, in the third statement, alpha is set to null, there is still a reference to the object.
There can be many copies of the reference to an object. Only when there is no reference to an object anywhere does the object become garbage.








Question 8:
(Review:) How can you determine what an object of a particular class can do?