Question

Exercise: Three UML class diagrams are given below. Class Employee is the superclass and the other two classes, Manager and Programmer, are subclasses of Employee.

Employee

- name: String

# salary: double

+ Employee( )

+ setEmployee( String, double ): void

+ getName( ): String

+ getSalary( ): double

+ print( ): void

Manager

Programmer

- numEmps: int

- language: String

+ Manager( )

+ setManager( String, double, int ): void

+ getNumEmps( ): int

+ getSalary( ): double

+ print( ): void [overridden]

+ Programmer( )

+ setProgrammer( String, double, String ): void

+ getLanguage( ): String

+ getSalary( ): double

+ print( ): void [overridden]

Note: The symbols -, #, and + mean private, protected, and public members respectively.

Answer the following questions based on the above diagrams:​

1.

Write the Java statement that makes the class Manager inherits the class Employee.

2.

Implement the default constructor of the class Manager.

3.

Implement the method setEmployee( … ) of the class Employee.

4.

Implement the method setProgrammer( … ) of the class Programmer.

5.

Implement the method getSalary( ) of the class Manager.

6.

Implement the overridden method print( ) of the class Manager.

7.

Declare an object named m of type Manager. Use the method setManager( … ) to set name, salary, and number of employees of object m to "Saleh Khalid", 17310, and 35.

8. Declare an object named p of type Programmer. Use the method setProgrammer( … ) to set name, salary, and language of object p to "Ahmed Hasan", 8550, and "Java".

9. Declare a reference variable named e of type Employee. Make e a reference to m. What e.print() will print? Then make e a reference to p. What e.print() will print?

Answer 1

class Employee
{ 
    String name;
    protected double salary;
    Employee()
    {
        
    }
    public void setEmployee( String n, double s)
    {
        name=n;
        salary=s;
    }
    public String getName( )
    {
        return name;
    }
    public double getSalary( )
    {
        return salary;
    }
    public void print( )
    {
        System.out.println("Name: "+name+" Salary: "+salary);
    }
}

class Manager extends Employee
{
    int numEmps;
    Manager()
    {
        
    }
    public void setManager( String n, double s, int e)
    {
        name=n;
        salary=s;
        numEmps=e;
    }
    public int getNumEmps()
    {
        return numEmps;
    }
    public double getSalary()
    {
        return salary;
    }
    public void print()
    {
        System.out.println("Name: "+name+" Salary: "+salary+" NumEmps: "+numEmps);
    }
}

class Programmer extends Employee
{
    
    String language;
    
    Programmer()
    {
        
    }
    public void setProgrammer(String n, double s, String l)
    {
        name=n;
        salary=s;
        language=l;
    }
    public String getLanguage()
    {
        return language;
    }
    public double getSalary( )
    {
        return salary;
    }
    public void print()
    {
        System.out.println("Name: "+name+" Salary: "+salary+" Language: "+language);
    }
    
}
class main
{
    public static void main (String[] args) 
    {
        Programmer p= new Programmer();
        p.setProgrammer("Ahmed Hasan", 8550,"Java");
        
        Manager m=new Manager();
        Employee e=m;
        e.print();
        e=p;
        e.print();
    }
}

I hope it helps.