CODEWITHSUNDEEP
javaarraysloopsrandom
Lou44
Lou44

Reputation: 65

Printing in Order and Reverse Order

The following code needs to print the random numbers in the array in order and reverse order. I have the reverse order printing but for some reason I can't seem to get it to print in original order. I'm not sure what to modify. What I currently have prints out a blank line for the "in order" and the numbers for "reverse order". What do I need to fix? Thank you!

public class RandomPrintOut
{
   //-----------------------------------------------------------------
   // 
   //-----------------------------------------------------------------
   public static void main (String[] args)
   {

       int numbers[] = new int [10]; 

       for (int i = 0 ; i < 10 ; i++) 
       { 
       numbers [i] = (int) (Math.random () * 100); 
       }



      System.out.println ("The size of the array: " + numbers.length);

      System.out.println ("The numbers in order:");

      for (int index = numbers.length+1; index <= 10; index++)
          System.out.print (numbers[index] + "  ");

      System.out.println ("\nThe numbers in reverse order:");

      for (int index = numbers.length-1; index >= 0; index--)
         System.out.print (numbers[index] + "  ");
   }
}

Upvotes: 0

Views: 13402

Answers (3)

Mengjun
Mengjun

Reputation: 3197

For the code below:

for (int index = numbers.length+1; index <= 10; index++)

Here the initialized value for index is number.length+1, this value is 10+1=11. This is greater than 10, as a result, the codition is never satisfied in this for-loop. That's why the array is not printed in order.

You need to do the change as follows:

Frome

for (int index = numbers.length+1; index <= 10; index++)
      System.out.print (numbers[index] + "  ");

to 

for (int index = 0; index <10; index++)
        System.out.print(numbers[index] + "  ");

Code after change is as follows:

public class RandomPrintOut { //----------------------------------------------------------------- // //----------------------------------------------------------------- public static void main (String[] args) {

   int numbers[] = new int [10]; 

   for (int i = 0 ; i < 10 ; i++) 
   { 
   numbers [i] = (int) (Math.random () * 100); 
   }

  System.out.println ("The size of the array: " + numbers.length);

  System.out.println ("The numbers in order:");

  for (int index = 0; index < 10; index++)
      System.out.print (numbers[index] + "  ");

  System.out.println ("\nThe numbers in reverse order:");

  for (int index = numbers.length-1; index >= 0; index--)
     System.out.print (numbers[index] + "  ");

} }

An result output printed in Console:

The size of the array: 10
The numbers in order:
31  50  49  99  29  54  41  16  7  21  
The numbers in reverse order:
21  7  16  41  54  29  99  49  50  31

Upvotes: 3

tumchaaditya
tumchaaditya

Reputation: 1297

public class RandomPrintOut {
   //-----------------------------------------------------------------
   // 
   //-----------------------------------------------------------------
   public static void main (String[] args) {

       int numbers[] = new int [10]; 

       for (int i = 0 ; i < 10 ; i++) { 
       numbers [i] = (int) (Math.random () * 100); 
       }



      System.out.println ("The size of the array: " + numbers.length);

      System.out.println ("The numbers in order:");

      for (int index = 0; index <= numbers.length-1; index++) {
          System.out.print (numbers[index] + "  ");
      }

      System.out.println ("\nThe numbers in reverse order:");

      for (int index = numbers.length-1; index >= 0; index--) {
         System.out.print (numbers[index] + "  ");
      }
   }
}

Upvotes: 0

Tyler Lee
Tyler Lee

Reputation: 2785

Take a closer look at the values of index over this loop

  for (int index = numbers.length+1; index <= 10; index++)
      System.out.print (numbers[index] + "  ");

Try doing it by hand and see what it looks like. That should help you identify the problem.

Upvotes: 0

Related Questions