Java program on Encapsulation

Write a Java program to create a BankAccount class with private instance variables such as Account Number and balance.
Provide public getter and setter methods to access and modify these variables.

public class BankAccount {
    // Private instance variables
    private String accountNumber;
    private double balance;

    // Constructor to initialize the bank account
    public BankAccount(String accountNumber, double initialBalance) {
        this.accountNumber = accountNumber;
        this.balance = initialBalance;
    }

    // Getter method for accountNumber
    public String getAccountNumber() {
        return accountNumber;
    }

    // Setter method for accountNumber
    public void setAccountNumber(String accountNumber) {
        this.accountNumber = accountNumber;
    }

    // Getter method for balance
    public double getBalance() {
        return balance;
    }

    // Setter method for balance
    public void setBalance(double balance) {
        this.balance = balance;
    }

    // Main method to test the BankAccount class
    public static void main(String[] args) {
        // Create a new bank account
        BankAccount account = new BankAccount("123456789", 1000.00);

        // Display account information
        System.out.println("Account Number: " + account.getAccountNumber());
        System.out.println("Balance: " + account.getBalance());

        // Update the account number and balance
        account.setAccountNumber("987654321");
        account.setBalance(1500.00);

        // Display updated account information
        System.out.println("Updated Account Number: " + account.getAccountNumber());
        System.out.println("Updated Balance: " + account.getBalance());
    }
}

output:

Get Harshh🎀’s stories in your inbox
Join Medium for free to get updates from this writer.
Remember me for faster sign in
Account Number: 123456789
Balance: 1000.0
Updated Account Number: 987654321
Updated Balance: 1500.0

02)Basic Encapsulation Create a class named Student. Add private fields: name (String), age (int), and grade (char). Provide public getter and setter methods for each of these fields. Write a main method that creates an instance of Student, sets the fields using the setter methods, and then retrieves and prints the values using the getter methods.

public class Student {
    // Private fields
    private String name;
    private int age;
    private char grade;

    // Getter and Setter for name
    public String getName() {
        return name;
    }

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

    // Getter and Setter for age
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        if (age >= 0) { // Ensuring age is non-negative
            this.age = age;
        } else {
            System.out.println("Age cannot be negative.");
        }
    }

    // Getter and Setter for grade
    public char getGrade() {
        return grade;
    }

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

    // Main method
    public static void main(String[] args) {
        // Create an instance of Student
        Student student = new Student();

        // Set fields using setter methods
        student.setName("Alice");
        student.setAge(20);
        student.setGrade('A');

        // Retrieve and print the values using getter methods
        System.out.println("Student Name: " + student.getName());
        System.out.println("Student Age: " + student.getAge());
        System.out.println("Student Grade: " + student.getGrade());
    }
}

Output:

Student Name: Alice
Student Age: 20
Student Grade: A