Week 9: Accessing Instance Variables and Methods, Garbage Collection,The Date Class, The Random Class

•Instance variables and methods are accessed via created objects. To access an instance variable the fully qualified path should be as follows:

/* First create an object */

ObjectReference = new Constructor();

 

/* Now call a variable as follows */

ObjectReference.variableName;

 

/* Now you can call a class method as follows */

ObjectReference.MethodName();

Garbage Collection:

As shown in the previous figure, after the assignment statement c1 = c2, c1 points to the same object referenced by c2. The object previously referenced by c1 is no longer referenced. This object is known as garbage. Garbage is automatically collected by JVM.

The Date Class:

Java provides a system-independent encapsulation of date and time in the java.util.Date class. You can use the Date class to create an instance for the current date and time and use its toString method to return the date and time as a string.