title: Link error (symbol from plugin)*
body: <p>Its been a while since ive coded in c++/c and im a little confused as to what im doing wrong</p>
  
  <p>I have three files, 2 .h and one .cpp.</p>
  
  <p>The files are as follow</p>
  
  <p>Base Menu</p>
  
  <pre><code>#include &lt;Adafruit_GFX.h&gt;
  #include &lt;Adafruit_SSD1306.h&gt;
  
  #define OLED_RESET 4
  #define SSD1306_LCDHEIGHT 64
  Adafruit_SSD1306 display(OLED_RESET);
  
  class BaseMenu {
  public:
      // for moving the menu up and down
      void moveDownMenu();
      void moveUpMenu();
      void selectMenu();
  
      // for changing the text and the positions
      void incrementText();
      void decrementText();
  
  protected:
      //
      char menuTitlePos1[20];
      char menuTitlePos2[20];
      char menuTitlePos3[20];
  
      bool is_menuPos1_selected = true;
      bool is_menuPos2_selected = false;
      bool is_menuPos3_selected = false;
  
  private:
      virtual void AbstractClass() = 0;
  };
  </code></pre>
  
  <p>MainMenu.h</p>
  
  <pre><code>#include "BaseMenu.h"
  #include &lt;string.h&gt;
  
  #define ARRAYSIZE 4
  
  class MainMenu : BaseMenu {
  private:
  
      // Constructor
      MainMenu() {};
  
  public:
      static void init();
  };
  </code></pre>
  
  <p>MainMenu.cpp</p>
  
  <pre><code>#include "MainMenu.h"
  
  void MainMenu::init() {
      // clearing display
      display.clearDisplay();
      display.display();
  
      display.setTextSize(1);
      display.setTextColor(WHITE);
      for (int i = 0; i &lt; ARRAYSIZE; i++) {
          if (i == 1) {
              display.setTextSize(1);
              display.setTextColor(BLACK, WHITE);
              //display.println(MainMenuTitles[i]);
           }
          else {
              display.setTextSize(1);
              display.setTextColor(WHITE);
              //display.println(MainMenuTitles[i]);
          }
      }
  
      display.display();
  }
  </code></pre>
  
  <p>When ever i go to build the code i get the following error.</p>
  
  <pre><code>MainMenu.cpp.o (symbol from plugin)*: In function display
  (.text+0x0)*: multiple definition of display
  TestingLibrary.cpp.o (symbol from plugin)*: (.text+0x0): first defined here
  
  collect2.exe*: error: ld returned 1 exit status
  </code></pre>
  
  <p>Can someone please shed some light as to what i'm doing wrong?</p>