Undefined reference problem

Ok, when I compile I get this message:

g++ -c main.cpp
g++ -c bell.cpp
g++ -c light.cpp
g++ -c clock.cpp
g++ -c person.cpp
g++ -c elevator.cpp
g++ -c building.cpp
g++ -o outlab02 main.o bell.o light.o clock.o person.o building.o
person.o: In function `Person::pressFloorButton(Building &)':
person.o(.text+0x3e): undefined reference to `FloorButton::FloorButton(void)'
person.o(.text+0x55): undefined reference to `FloorButton::pressButton(Building &, int)'
collect2: ld returned 1 exit status
make: *** [outlab02] Error 1

I have no idea what's wrong. All the files appear to compile, and I've checked all the methods it asks for:

In Person implementation:

Code:

---

/****pressFloorButton****/
void Person::pressFloorButton(Building& build)
{
  FloorButton button = FloorButton();
  button.pressButton(build, floor);
}

---

In FloorButton implementation:

Code:

---

/****buttonPressed()****/
void FloorButton::pressButton(Building& build, int floor)
{  build.buildingElevator.callElevator(floor);
}

---

In FloorButton definition:

Code:

---

/**
    * pressButton()                                           
    * Author: Jeff Balboni                                                                                                                                                                                           
    * Description: Signals for Elevator to come to floor                     
    **/
    void pressButton(Building& build, int floor);

---

Help?

(sorry about the width, I dunno what's with that)

What is this line supposed to do?

FloorButton button = FloorButton();

If you are trying to create an instance of FloorButton using the default constructor, I would suggest this:

FloorButton button;

Don't know if that is your problem but it just looks suspicious.

An undefined reference to a function like those you're getting means you either did not write the functions or the source file is not compiled and cannot be found. Simply put the compiler CANNOT find those functions.

Quote:

---

g++ -o outlab02 main.o bell.o light.o clock.o person.o building.o

---

elevator.o is not being linked.