Question

JAVA

Lab Assignment #13:  Looping Lab with both types of loops.

• This lab demonstrates the use of the While Loop and the Do While Loop as error checking mechanisms.
• You will be using each of these loops to solve the same problem.
• Please put them both in the same program.
• When you test the code, you will not see a difference in the way they execute - but there will be a difference in the logic when writing the code.
• You will want to write a refined algorithm for both to see the logic differences.

Lab 13 Part a:

Using a While Loop, write the code that does the following:

• Prompts the User for a score between 0 and 100 (inclusive).
• Repeats the prompt until the User enters a valid number within the specified range.

Lab 13 Part b:

Using a Do While Loop, write the code that does the following:

• Prompts the User for a score between 0 and 100 (inclusive).
• Continues to prompt for scores until the User enters a valid number within the specified range.

Include the following in your programs:

• A refined algorithm for each looping structure.
• Internal documentation for your code.

NOTE 1:

• DO NOT use the "return 0" code, end, break, or exit to force an exit from within your IF/ELSE structure.  Declare all variables within the data declaration section.
  • Let the program progress to the end of the main function.
  • The end of the main function is the only place that the “return 0” should be placed.
  • A SWITCH statement is the only place that the break command should be used.
• DO NOT use the "continue" statement.

NOTE 2:

1. Declare all variables within the data declaration section of each class and method.  (-.1)
2   Do not get input on the same line as a variable declaration.  (-.1)
3. Do not place an equation for computation on the same line as declaring a variable.  (-.1)
3. Do not place an equation for computation on the same line as an input statement.  (-.1)

Answer 1

Solution :

Initiallize n to -1. For both the while and do-while loops, write the condition for n to not be in the range [0-100] and continue till the condition is not satisfied.  

Following is the Java code for the same :

import java.util.*;
class Main { 
        public static void main(String args[]) 
        { 

                // initialisation expression 
                int n; 
                n=-1;
                Scanner sc= new Scanner(System.in); //System.in is a standard input stream.
                System.out.println("\nWhile loop demonstration : \n");
                while(n<0 || n>100) { 

                        // Prompt the user 
                        System.out.println("\nEnter a score between 0 and 100(inclusive)\n");
                        n=sc.nextInt();
                } 
            
            System.out.println("\nDo While loop demonstration : \n");
            do
            {   // Prompt the user 
                        System.out.println("\nEnter a score between 0 and 100(inclusive)\n");
                        n=sc.nextInt();
                
            }
                while(n<0 || n>100);
        } 
} 

Code demo for reference :