001 /** 002 * Exercise 5.6 from the book. 003 * 004 * @author Kristian Torp, torp (at) cs (dot) aau (dot) dk 005 * @version 1.0 006 */ 007 public class Exercise5_6 { 008 // instance variables 009 public int publicI; 010 011 protected int protectedI; 012 013 private int privateI; 014 015 int friendlyI; 016 017 /** 018 * Constructor for objects of class Exercise5_6 019 */ 020 public Exercise5_6() { 021 publicI = 10; 022 protectedI = 20; 023 privateI = 30; 024 friendlyI = 40; 025 } 026 027 /** 028 * Shows all public instance variables 029 */ 030 public void showPublic() { 031 System.out.println("publicI: " + publicI); 032 } 033 034 protected void showProtected() { 035 System.out.println("protectedI: " + protectedI); 036 } 037 038 private void showPrivate() { 039 System.out.println("privateI: " + privateI); 040 } 041 042 void showFriendly() { 043 System.out.println("friendlyI: " + friendlyI); 044 } 045 046 /** 047 * Main which some objects 048 */ 049 public static void main(String args[]) { 050 Exercise5_6 c1 = new Exercise5_6(); 051 c1.showPublic(); 052 c1.showProtected(); 053 c1.showPrivate(); 054 c1.showFriendly(); 055 056 c1.publicI = 11; 057 c1.showPublic(); 058 c1.protectedI = 21; 059 c1.showProtected(); 060 c1.privateI = 31; 061 c1.showPrivate(); 062 c1.friendlyI = 41; 063 c1.showFriendly(); 064 } 065 }