Local Object References : Method Variable « Java Source And Data Type « SCJP

import java.util.Date;
public class TimeTravel {
  public static void main(String [] args) {
    Date date;
    if (date == null)
      System.out.println("date is null");
  }
}

The local variable date may not have been initialized

1.21.Method Variable
	1.21.1.	Local (Automatic/Stack/Method) Variables
	1.21.2.	local variables can be marked final.
	1.21.3.	Local variable has its scope limited to the method who declares it
	1.21.4.	It is legal to declare a local variable with the same name as an instance variable; this is called "shadowing".
	1.21.5.	Attempt to use a loop variable outside the code block of the loop.
	1.21.6.	Local Object References
	1.21.7.	Shadow an instance variable by declaring a local variable of the same name directly or as part of an argument
	1.21.8.	Shadowed variable is an object reference