Function in separate Class file isn't working

Hello. I’m trying to learn L-systems and tried to make an algae class that provides N amounts of generations. However when I’m trying to test the function OF refuses to build saying:

Undefined symbols for architecture x86_64:
“algaeClass::generateAlgae(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, int)”, referenced from:
ofApp::setup() in ofApp.o
ld: symbol(s) not found for architecture x86_64

Here’s my code this far, it has been ages since I last used OF so pretty much forgot everything already, so bare with me:

algae hpp file

//  algae.hpp
//  omaLsystem1
#ifndef lsystem_hpp
#define lsystem_hpp

#include <stdio.h>
#include <string>
#include "ofMain.h"

class algaeClass {

    string generateAlgae(string word, int iterations);

#endif /* algae_hpp */

algae cpp file

//  algae.cpp
//  omaLsystem1

#include "algae.hpp"

string generateAlgae(string word, int iterations) {
    if (iterations == 0) {
        return word;
    string newWord = "";
    for (int i = 0; i < word.size(); i++) {
        if (word[i] == 'A') {
            newWord += "AB";
        if (word[i] == 'B') {
            newWord += "A";
    string toReturn = "";
    toReturn += generateAlgae(newWord, iterations-1);
    return toReturn;


#pragma once

#include "ofMain.h"
#include <string>
#include "algae.hpp"
#include <iostream>

class ofApp : public ofBaseApp{

		void setup();
		void update();
		void draw();

		void keyPressed(int key);
		void keyReleased(int key);
		void mouseMoved(int x, int y );
		void mouseDragged(int x, int y, int button);
		void mousePressed(int x, int y, int button);
		void mouseReleased(int x, int y, int button);
		void mouseEntered(int x, int y);
		void mouseExited(int x, int y);
		void windowResized(int w, int h);
		void dragEvent(ofDragInfo dragInfo);
		void gotMessage(ofMessage msg);

    algaeClass algae;		

Then the function is called with algae.generateAlgae(“A”, 6); etc.


Somehowe your code became unreadable. Could you edit your post and add these lines before and after?


…code here…


Oh right, it got really messy with the formatting, sorry about that. Now it should be a bit clearer. The function is probably incorrect, I couldn’t test it yet because of the stated error. Hope it makes more sense now.

It looks like you’re missing



string algaeClass::generateAlgae(string word, int iterations)

in the cpp file.

Oh yeah that was it! Thank you very much! I assume that you need to use that :: notation always because of the namespace?