Managing Data with Lists and Classes in Java

Hello, Space Explorer! Today, we’re going to discuss a practical and essential topic in Java: managing data using lists and classes. To practice this concept, we will build a simple Student Management System. Specifically, we will create a class that stores students and their grades. This hands-on approach will help us understand how lists and objects can be used effectively in real-world applications. Are you excited? Great, let's dive in!

To accomplish our task, we need to implement three primary methods within our class:

• addStudent(String name, int grade): This method allows us to add a new student and their grade to our list. If the student is already on the list, their grade will be updated.
• getGrade(String name): This method retrieves the grade for a student given their name. If the student is not found, it returns null.
• removeStudent(String name): This method removes a student from the list by their name. It returns true if the student is successfully removed and false if the student is not found.

Does that sound straightforward? Fantastic, let's break it down step-by-step.

Let’s start by defining our StudentManager class, which will use a list of objects to manage students and their grades. We will also define a Student class to represent individual student data.

import java.util.ArrayList;

class StudentManager {
    private ArrayList<Student> students;

    public StudentManager() {
        students = new ArrayList<Student>();
    }
}

class Student {
    private String name;
    private int grade;

    public Student(String name, int grade) {
        this.name = name;
        this.grade = grade;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getGrade() {
        return grade;
    }

    public void setGrade(int grade) {
        this.grade = grade;
    }
}

public class Solution {
    public static void main(String[] args) {
        StudentManager manager = new StudentManager();
        System.out.println("StudentManager instance created.");
    }
}