public class Company {

    private String companyName;
    private ArrayList<Employee>employees;

    public Company(String companyName) {
        this.companyName = companyName;
        this.employees = new ArrayList<Employee>();
    }

    public boolean addNewEmployee(Employee employee){
    if (findEmployee(employee.getEmployeeName())>=0){
        System.out.println("Employee is already existing.");
        return false;
    }
    employees.add(employee);
    return true;
    }

    private int findEmployee (Employee employee){
        return employees.indexOf(employee);
    }

    private int findEmployee ( String employeeName){
        for ( int i = 0; i < employees.size();i++){
            Employee employee = employees.get(i);
            if (employee.getEmployeeName().equals(employeeName)){
                return i;
            }
        }
        return -1;
    }

}