Java

TOPIC 44 – ARRAYS 1

 

LESSON WORK

 

 

 

 

QUESTION #2 (SELF-CHECK)

 

SOLUTIONS

A)

     int[] primes = {2, 3, 5, 7, 11, 13, 17, 19};

     System.out.println(Arrays.toString(primes));

 

B)

     int[] faves = new int[5];

 

     faves[0] = 13;

     faves[1] = 7;

     faves[2] = 0;

     faves[3] = 314;

     faves[4] = 60;

    

     System.out.println(Arrays.toString(faves));

 

 

C)

     boolean[] flags = new boolean[40];

        

     for (int i=0; i<flags.length; i++)

     {

         if (i % 2 == 0) //if even index

         {

              flags[i] = true;

         }

         else  //odd index

         {

              flags[i] = false;

         }

     }

        

     System.out.println(Arrays.toString(flags));

 

D)

     int[] arr = new int[10];

 

     for (int i=0; i<arr.length; i++)

     {

         arr[i] = i * 2;

     }

     System.out.println(Arrays.toString(arr));

 

Note: In the above example, I named the control variable i.  But based on the question, perhaps I should have used j.

 

E)

 

     int[] fib = new int[10];

 

     fib[0] = 1;

     fib[1] = 1;

 

     for (int i=2; i<fib.length; i++)

     {

         fib[i] = fib[i-1] + fib[i-2];;

     }

     System.out.println(Arrays.toString(fib));



          Note the above code will output:

 

         [1, 1, 2, 3, 5, 8, 13, 21, 34, 55]

 

F)

 

   double[] results = {9.6, 9.5, 9.9, 10.0, 9.4};

        

     for (int i = 0; i < results.length; i++)

     {

          System.out.println(results[i]);

     }