12_Inheritance.java

/**
 * You are given two classes, Person and Student, where Person is the base class and Student is the derived class. 
 * Completed code for Person and a declaration for Student are provided for you in the editor. 
 * Observe that Student inherits all the properties of Person.
 *
 * Complete the Student class by writing the following:
 *
 * A Student class constructor, which has parameters:
 * A string, firstName.
 * A string, lastName.
 * An integer, id.
 * An integer array (or vector) of test scores, scores.
 *
 * A char calculate() method that calculates a Student object's average and returns the grade character 
 * representative of their calculated average:
 * O: 90 <= a <= 100
 * E: 80 <= a < 90
 * A: 70 <= a < 80
 * P: 40 <= a < 70
 * D: 40 <= a < 55
 * T: a < 40
 */
import java.util.*;

class Person {
	protected String firstName;
	protected String lastName;
	protected int idNumber;
	
	// Constructor
	Person(String firstName, String lastName, int identification){
		this.firstName = firstName;
		this.lastName = lastName;
		this.idNumber = identification;
	}
	
	// Print person data
	public void printPerson(){
		 System.out.println(
				"Name: " + lastName + ", " + firstName 
			+ 	"\nID: " + idNumber); 
	}
	 
}

class Student extends Person{
	private int[] testScores;

    /*	
    *   Class Constructor
    *   
    *   @param firstName - A string denoting the Person's first name.
    *   @param lastName - A string denoting the Person's last name.
    *   @param id - An integer denoting the Person's ID number.
    *   @param scores - An array of integers denoting the Person's test scores.
    */
    Student(String firstName, String lastName, int id, int[] scores){
        super(firstName, lastName, id);
        this.testScores = scores;
    }

    /*	
    *   Method Name: calculate
    *   @return A character denoting the grade.
    */
    public char calculate(){
        int result = 0;
        for(int i = 0; i < testScores.length; i++){
            result += testScores[i];
        }
        result /= testScores.length;
        
        if(result >= 90) return 'O';
        else if(result >= 80) return 'E';
        else if(result >= 70) return 'A';
        else if(result >= 55) return 'P';
        else if(result >= 40) return 'D';
        else return 'T';
    }
}

class Solution {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String firstName = scan.next();
		String lastName = scan.next();
		int id = scan.nextInt();
		int numScores = scan.nextInt();
		int[] testScores = new int[numScores];
		for(int i = 0; i < numScores; i++){
			testScores[i] = scan.nextInt();
		}
		scan.close();
		
		Student s = new Student(firstName, lastName, id, testScores);
		s.printPerson();
		System.out.println("Grade: " + s.calculate());
	}
}