PreLab 9: More Loops

1. Trace the execution of the following loop by showing the value of each variable at each iteration in the table next to the code.

         final int LIMIT = 15;                num          sum       
         int num = 1;                         ---          ---  
         int sum = 0; 
      
         while (num < LIMIT)
         {
            num = num + 3;
            sum = sum + num;
         }
   
         System.out.println ("Last number is " +  num + " and sum is " + sum);
   

2. What is printed by the above code?

    

    

    

3. Write a for loop equivalent to the while loop above.

    

    

    

    

    

    

4. Complete the following code to print the string read in backwards. Use a for loop.

         String str;
         int length;
         System.out.print ("Enter a string of characters: ");
         str = scan.nextLine();
   
         // Find the length of str
   
   
         ________________________________________________________________;
   
         // Write a for loop to print the string backwards
   
   
   
   
   
   
   
   
   
   
   

5. The following nested loop prints a triangle of stars (see page 250 of your text - it shows the whole program and the output).

         final int MAX_ROWS = 10;
         for (int row = 1; row <= MAX_ROWS; row++)
         {
            for (int star = 1; star <= row;  star++)
               System.out.print ("*");
    
            System.out.println();
        }
   

   Modify the code to print the "upside down" triangle in part (a) of Programming Project 5.10 on page 286 of the textbook.

    

    

    

6. Write a fragment of code that reads in a sequence of numbers and finds the smallest number read in. Use a do ... while loop. Control the loop by asking the user if there are more numbers to enter. Read the answer into a String variable. You may assume the numbers will be in the range -1000 to +1000.