Question

You should create a driver class that calls the implementation in a separate class. You should not rely on static methods in the implementation class.

Specific methods to be defined/implemented

1. Create and use each primitive type.

2. Create a constant that can be used as a sentinel.

3. Use an if to control program execution.

4. Use a for, while and do while loop in your program.

5. Create an array in your program, add values to it and print it.

Specific Requirements: Your program should allow the user to enter a selection for the different steps in your program. For example, one of your conditions could be to allow the user to enter a list of names. Another could be to print this list of names. You could add a sort routine, to sort in ascending order. There are no requirements to execute specific functionality, you must use each of the concepts listed above.

Answer 1

Solution: There are total 2 files (Driver.java and Student.java)

Driver.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

//Driver class to run the program
public class Driver {
    public static void main(String[] args) throws IOException {

        Student obj = new Student();

        System.out.println("Please Enter your choice as below \n");
        System.out.println("Enter (1) to enter list of names separated by space");
        System.out.println("Enter (2) to print list of names using for loop");
        System.out.println("Enter (3) to print list of names using while loop");
        System.out.println("Enter (4) to print all names in ascending order");
        System.out.println("Enter (5) to print all names in descending order");
        System.out.println("Enter (0) to exit");
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("\n\nEnter your choice\n");
        int choice = Integer.parseInt(bufferedReader.readLine());
        do
        {
            switch (choice)
            {
              case 0:
                  System.exit(1);
                    break;
              case 1:
                  System.out.println("\nEnter Names\n");
                  String[] namelist = bufferedReader.readLine().split(" ");
                  obj.addStudentNames(namelist);
                  break;
              case 2:
                  obj.printNamesUsingForLoop();
                  break;
              case 3:
                  obj.printNamesUsingWhileLoop();
                  break;
              case 4:
                  obj.printNamesAscendingOrder();
                  break;
              case 5:
                  obj.printNamesDescendingOrder();
                  break;
              default:
                  System.out.println("You have entered invalid choice ");
            }
            System.out.println("\n\nEnter your choice");
            choice = Integer.parseInt(bufferedReader.readLine());
        }while (choice >= 0 && choice  <= 5 );

    }
}

Student.java

import java.util.Arrays;
import java.util.Collections;

public class Student {
    private String studentnames[];
    private static int count = 0;
    //constant
    private final static String collegename = "UCLA";

    //Function to add the names to the array
    public void addStudentNames(String[] names){
        //Initialize only first time
        if(count == 0)
           studentnames = new String[100];
        for(String name : names)
        {
            studentnames[count++] = name;
        }
        System.out.println("Total Names Successfully Added = "+count);
    }

    //Function to print the name list using for loop
    public void printNamesUsingForLoop(){
        //check if name array is null
        if(studentnames == null) {
            System.out.println("\n\nSorry you don't have any names to print");
            return;
        }
        for(int i = 0; i < count; i++){
            System.out.println("Name : "+studentnames[i]+"   College : "+collegename);
        }
    }

    //Function to print the name list using while loop
    public void printNamesUsingWhileLoop(){
        //check if name array is null
        if(studentnames == null) {
            System.out.println("\n\nSorry you don't have any names to print");
            return;
        }
        int i = 0;
        while (i < count)
        {
            System.out.println("Name : "+studentnames[i]+"   College : "+collegename);
            i++;
        }
    }

    //Function will print the names in ascending order
    public void printNamesAscendingOrder(){
        //check if name array is null
        if(studentnames == null) {
            System.out.println("\n\nSorry you don't have any names to print");
            return;
        }
        String[] temparray = Arrays.copyOf(studentnames, count);
        //sort the elements in ascending order
        Arrays.sort(temparray);
        for(String name : temparray)
        {
            System.out.println("Name : "+name+"   College : "+collegename);
        }
    }

    //Function will print the names in descending order
    public void printNamesDescendingOrder(){
        //check if name array is null
        if(studentnames == null) {
            System.out.println("\n\nSorry you don't have any names to print");
            return;
        }
        String[] temparray = Arrays.copyOf(studentnames, count);
        //sort the elements in descending order
        Arrays.sort(temparray, Collections.reverseOrder());
        for(String name : temparray)
        {
            System.out.println("Name : "+name+"   College : "+collegename);
        }
    }
}

OUTPUT:

Please Enter your choice as below

Enter (1) to enter list of names separated by space
Enter (2) to print list of names using for loop
Enter (3) to print list of names using while loop
Enter (4) to print all names in ascending order
Enter (5) to print all names in descending order
Enter (0) to exit

Enter your choice

2

Sorry you don't have any names to print

Enter your choice
1

Enter Names

John Wilson Angelina Joli
Total Names Successfully Added = 4

Enter your choice
2
Name : John College : UCLA
Name : Wilson College : UCLA
Name : Angelina College : UCLA
Name : Joli College : UCLA

Enter your choice
3
Name : John College : UCLA
Name : Wilson College : UCLA
Name : Angelina College : UCLA
Name : Joli College : UCLA

Enter your choice
4
Name : Angelina College : UCLA
Name : John College : UCLA
Name : Joli College : UCLA
Name : Wilson College : UCLA

Enter your choice
5
Name : Wilson College : UCLA
Name : Joli College : UCLA
Name : John College : UCLA
Name : Angelina College : UCLA

Enter your choice
0

Process finished with exit code 1