mod5ans.lst

Mcgraw-Hill - Java 2 - A Beginner S Guide, 2Nd Ed - 2003 -prog.

listing 1
// Average 10 double values. 
class Avg { 
  public static void main(String args[]) { 
    double nums[] = { 1.1, 2.2, 3.3, 4.4, 5.5, 
                      6.6, 7.7, 8.8, 9.9, 10.1 }; 
    double sum = 0; 
 
    for(int i=0; i < nums.length; i++) 
      sum += nums[i]; 
 
    System.out.println("Average: " + sum / nums.length); 
  } 
}

listing 2
// Demonstrate the Bubble sort with strings.  
class StrBubble {   
  public static void main(String args[]) {   
    String strs[] = { 
                     "this", "is", "a", "test", 
                     "of", "a", "string", "sort"  
                    }; 
    int a, b; 
    String t;   
    int size;   
   
    size = strs.length; // number of elements to sort   
   
    // display original array   
    System.out.print("Original array is:");  
    for(int i=0; i < size; i++)  
      System.out.print(" " + strs[i]);   
    System.out.println();   
   
    // This is the bubble sort for strings.   
    for(a=1; a < size; a++)   
      for(b=size-1; b >= a; b--) {   
        if(strs[b-1].compareTo(strs[b]) > 0) { // if out of order   
          // exchange elements    
          t = strs[b-1];   
          strs[b-1] = strs[b];   
          strs[b] = t;   
        }   
      }   
   
    // display sorted array   
    System.out.print("Sorted array is:");   
    for(int i=0; i < size; i++)  
      System.out.print(" " + strs[i]);   
    System.out.println();  
  }  
}

listing 3
// An improved XOR cipher. 
class Encode {   
  public static void main(String args[]) {  
    String msg = "This is a test";   
    String encmsg = "";  
    String decmsg = "";  
    String key = "abcdefgi";  
    int j; 
 
    System.out.print("Original message: ");  
    System.out.println(msg);  
  
    // encode the message  
    j = 0; 
    for(int i=0; i < msg.length(); i++) { 
      encmsg = encmsg + (char) (msg.charAt(i) ^ key.charAt(j)); 
      j++; 
      if(j==8) j = 0; 
    }  
  
    System.out.print("Encoded message: ");  
    System.out.println(encmsg);  
  
    // decode the message  
    j = 0; 
    for(int i=0; i < msg.length(); i++) { 
      decmsg = decmsg + (char) (encmsg.charAt(i) ^ key.charAt(j)); 
      j++; 
      if(j==8) j = 0; 
    }  
     
    System.out.print("Decoded message: ");  
    System.out.println(decmsg);  
 
  }  
}