Java Reference
In-Depth Information
Self-Test Exercises
3. Write a method called getNextYear that could be added to the class
DateSecondTry in Display 4.2. The method getNextYear returns an int value
equal to the value of the year instance variable plus one.
Display 4.3 Using the Class in Display 4.2
1 public class DemoOfDateSecondTry
2{
3 public static void main(String[] args)
4
An invocation of a void method is a
statement.
{
5
DateSecondTry date = new DateSecondTry();
6
date.readInput();
7
int dayNumber = date.getDay();
8
System.out.println("That is the " + dayNumber
9
+ "th day of the month.");
10
}
An invocation of a method that returns a value is an expression that can be
used anyplace that a value of the type returned by the method can be used.
11
}
Sample Dialogue
Enter month, day, and year.
Do not use a comma.
July 4 1776
That is the 4th day of the month.
Local Variables
Look at the definition of the method readInput() given in Display 4.2. That method
definition includes the declaration of a variable called keyboard . A variable declared
within a method is called a local variable . It is called local because its meaning is local
to—that is, confined to—the method definition. If you have two methods and each of
them declares a variable of the same name—for example, if both were named key-
board —they would be two different variables that just happen to have the same name.
Any change that is made to the variable named keyboard within one method would
have no effect upon the variable named keyboard in the other method.
As we noted in Chapter 1, the main part of a program is itself a method. All variables
declared in main are variables local to the method main . If a variable declared in main
local variable
 
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