Question

1. Check errors and revise/update this java code below and update with OOp class; at least make two classes, use java library, validate user input, format and create UML/Pseudocode and flowchart for the code.

import java.util.Scanner;

public class TestScore

{

   public static void main(String[] args) {

       String firstName;

       String lastName;

       int numTest;

       int i;

       int score;

       double totalScore;

       double avgScore;

       String grade;

       Scanner input = new Scanner(System.in);

       System.out.println("Enter First Name");

       firstName = input.nextLine();

       System.out.println("Enter Last Name");

       lastName = input.nextLine();

       System.out.println("How many test score do you want to enter: ");

       numTest = input.nextInt();

       while(!input.hasNextDouble())

       {

           numTest = input.nextInt();

           System.out.println("Invalid entry, try again");

       }

       totalScore = 0;

       for (i = 0; i <= numTest - 1; i++) {

           score = input.nextInt();

           totalScore = totalScore + score;

       }

       avgScore = totalScore / numTest;

       if (avgScore >= 90) {

           grade = "A";

       } else {

           if (avgScore >= 80) {

               grade = "B";

           } else {

               if (avgScore >= 75) {

                   grade = "C";

               } else {

                   if (avgScore >= 50) {

                       grade = "D";

                   } else {

                       grade = "F";

                   }

               }

           }

       }

       System.out.println(firstName + " " + lastName + " " + avgScore + " " + grade);

   }

}

Answer 1

Updated code with OOP's classes is given below-

There are 2 classes- First is PersonalInfo and Second is Marks class. And then, we have a class Main, that has main method.

import java.util.Scanner;

class PersonalInfo{
String firstName;
String lastName;
  
public PersonalInfo(){
firstName="";
lastName="";
}
  
public void setFirstName(String fname){
firstName=fname;
}
  
public void setLastName(String lname){
lastName=lname;
}
  
public String getFirstName(){
return firstName;
}
  
public String getLastName(){
return lastName;
}
  
  
}

class Marks{
  
int numTest;
int i;
int score;
double totalScore=0;
double avgScore;
String grade;
  
public void setNumTest(int n){
numTest=n;
}
  
public void setScore(int s){
score=s;
totalScore=totalScore+s;
}
  
public int getNumTest(){
return numTest;
}
  
public int getScore(){
return score;
}
  
  
  
public void calResult(){
avgScore=totalScore/numTest;
if (avgScore >= 90) {

grade = "A";

} else {

if (avgScore >= 80) {

grade = "B";

} else {

if (avgScore >= 75) {

grade = "C";

} else {

if (avgScore >= 50) {

grade = "D";

} else {

grade = "F";

}

}

}

}
  
System.out.println("Your average is: "+avgScore);
System.out.println("Your grade is: "+grade);
}
  
  
}

public class Main

{

public static void main(String[] args) {

String firstName, lastName, grade;
int numTest, i, score;
double totalScore, avgScore;

PersonalInfo p=new PersonalInfo();
Marks m=new Marks();
Scanner input = new Scanner(System.in);

System.out.println("Enter First Name");
firstName = input.nextLine();
p.setFirstName(firstName);

System.out.println("Enter Last Name");
lastName = input.nextLine();
p.setLastName(lastName);

System.out.println("How many test score do you want to enter: ");

numTest = input.nextInt();
  
if(numTest<=0){
while(numTest<=0){
System.out.println("Enter correct number of tests!!!");
numTest = input.nextInt();
}
}
m.setNumTest(numTest);

for (i = 0; i <= numTest - 1; i++) {

System.out.println("Enter the marks for test "+(i+1)+":");
score = input.nextInt();
m.setScore(score);

}

m.calResult();
System.out.println("For Student with firstName: "+p.getFirstName()+" and LastName: "+p.getLastName());

}

}

UML Class Diagram for each class is given below-

1) PersonalInfo class

2) Marks class

3) Main class

Do tell if there is any problem in answer!!! Will take care in future :)