Problem with "U8glib.h" library (Noob)

Having problems with a code from my begginers guide book to Arduino.
The code was working fine to beggin with, but (seemingly) without me doing any change to the code it stop working. I think the problem is connected to the "U8gilb" library.

I case i was not obvious i am new to Arduino (and coding in general)

My code:

#include "U8glib.h"

U8GLIB_SSD1306_128X64 oled(U8G_I2C_OPT_NONE);

int n=0;


void loop(){
  //Refresh picture
  oled.firstPage();
  do {
    draw();
  }while(oled.nextPage());

  //Continue drawing line until n<30
  if(n < 30) {
    n++;
  }
  
  //Wait 5000 ms and then remove line
  else{
    delay (5000);
    n = 0;
  }
}
 
void draw() {

  //Draw pixels
  oled.drawPixel (11, 44);
  oled.drawPixel (13, 44);

  //Draw line
  oled.drawLine(12, 28, 12, 60);
  oled.drawLine(12, 60, 127, 60);
  oled.drawLine(12, 60, 12 + n*4, 60-n);
  
  //Print strings
  oled.drawStr(0,10, "My Arduino");
  oled.drawStr(0,23, "knowledge");
  oled.drawStr(0,60, "0");
  oled.drawStr(0,40, "1");
}

Errors:

Arduino:1.8.8 (Windows Store 1.8.19.0) (Windows 10), Kort"Arduino/Genuino Uno"

C:\Users\Henni\AppData\Local\Temp\ccz4ZLaJ.ltrans0.ltrans.o: In function `main':

C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.19.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino/main.cpp:43: undefined reference to `setup'

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Help would be much appreciated :slight_smile:

There is no setup in your code...

A minimal arduino code is made of declarations, a setup function which runs only once, and a loop function running in a loop.

Feel stupid now, i thought that, since i did not write anything i the setup code, it was unnecessary.

Thanks for helping anyways :slight_smile:

No worries, setup as well as loop, can remain empty but it must stay in the code