Quick question (java or C++)

public class Employee {
     
    private String firstName; 
    private String lastName; 
    private double monthlySalary;
 
    public Employee(String name, String name2, double salary) {
        firstName = name;
        lastName = name2;
        monthlySalary = salary;
    }
 
    public void setFirstName(String name) {
        firstName = name;
    }
 
    public String getFirstName() {
        return firstName;
    }
 
    public void setLastName(String name) {
        lastName = name;
    }
 
    public String getLastName() {
        return lastName;
    }
 
    public void setmonthlySalary(double salary) {
        monthlySalary = salary;
    }
 
    public double getmonthlySalary() {
        return monthlySalary;
    }
 
    public double yearlySalary() {
        double yearlySalary;
        yearlySalary = (monthlySalary * 12);
        return yearlySalary;
    }
 
    public double yearlySalaryIncrease() {
        double yearlySalaryIncrease;
        yearlySalaryIncrease = (((yearlySalary() * (0.1)) + yearlySalary()));
        return yearlySalaryIncrease;
    }
 
    public void displayYearlySalary() {
        System.out.printf("%s %s's Yearly Salary is $%.2f\n", firstName, lastName,
           yearlySalary());
    }
 
    public void displayYearlySalaryIncrease() {
        System.out.printf("%s %s = $%.2f\n", firstName, lastName, yearlySalaryIncrease());
    }
 
}

import java.util.Scanner;
 
public class EmployeeTest {
    public static void main(String[] args) {
         
        Employee employee1 = new Employee("first", "last", 0.0);
        Employee employee2 = new Employee("first", "last", 0.0);
 
    Scanner input = new Scanner(System.in);
         
        String firstName;
        String lastName;
        double monthlySalary;
 
        System.out.println("Enter details of employee1:\n");
         
        System.out.print("Enter First Name: ");
        firstName = input.next();
        employee1.setFirstName(firstName);
        employee1.getFirstName();
        System.out.print("Enter Last Name: ");
        lastName = input.next();
        employee1.setLastName(lastName);
        employee1.getLastName();
        System.out.print("Enter Monthly Salary: ");
        monthlySalary = input.nextDouble();
        if (monthlySalary > 0) //if monthly salary is not positive do not set its value
            employee1.setmonthlySalary(monthlySalary);
        employee1.getmonthlySalary();
 
        System.out.println();
 
        System.out.println("Enter details of employee2:\n");
 
        System.out.print("Enter First Name: ");
        firstName = input.next();
        employee2.setFirstName(firstName);
        employee2.getFirstName();
        System.out.print("Enter Last Name: ");
        lastName = input.next();
        employee2.setLastName(lastName);
        employee2.getLastName();
        System.out.print("Enter Monthly Salary: ");
        monthlySalary = input.nextDouble();
        if (monthlySalary > 0) //if monthly salary is not positive do not set its value
            employee2.setmonthlySalary(monthlySalary);
        employee2.getmonthlySalary();
 
        System.out.println();
 
        employee1.yearlySalary();
        employee2.yearlySalary();
 
        employee1.displayYearlySalary();
 
        System.out.println();
 
        employee2.displayYearlySalary();
 
        System.out.println();
 
        employee1.yearlySalaryIncrease();
        employee2.yearlySalaryIncrease();
 
        System.out.printf("Congratulations to %s %s and %s %s. You just earned"
                + " for yourselves a 10%c increase in your yearly salaries. "
                + "\nYour new yearly salaries are:\n\n", employee1.getFirstName(),
                employee1.getLastName(), employee2.getFirstName(), 
                employee2.getLastName(), '%');
 
        employee1.displayYearlySalaryIncrease();
 
        System.out.println();
 
        employee2.displayYearlySalaryIncrease();
 
    }
}