7-Segment Basic Digits

int SEG_A = 4; //define which pins connect to which segments   
int SEG_B = 5;
int SEG_C = 8;
int SEG_D = 7;
int SEG_E = 6;
int SEG_F = 3;
int SEG_G = 2;
int SEG_DOT = 9;

int pins[] = {SEG_A, SEG_B, SEG_C, SEG_D, SEG_E, SEG_F, SEG_G, SEG_DOT};
int numPins = 8;

int pause = 500;

void setup() {
  // put your setup code here, to run once:
  for (int i = 0; i < numPins; i++){
    pinMode(pins[i], OUTPUT);
  }
  turnOffAllSegments();
}

void loop() {
  // put your main code here, to run repeatedly:
  int largestDigit = 9;

  for (int i = 0; i <= largestDigit; i++){
    displayDigit(i);
    delay(pause);
  }
}

void turnOffAllSegments(){
  for (int i = 0; i < 8; i++){
    digitalWrite(pins[i], HIGH);
  }
}

void displayDigit(int num){

  turnOffAllSegments();
  
  if (num == 0){ //Segments ABCDEF
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[4], LOW);
    digitalWrite(pins[5], LOW);
  }
  else if (num == 1){ //segments BC
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
  }
  else if (num == 2){ //segments ABDEG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[4], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 3){ //segments ABCDG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 4){ //segments BCFG
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[5], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 5){ //segments ACDFG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[5], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 6){ //segments ACDEFG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[4], LOW);
    digitalWrite(pins[5], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 7){ //segments ABC
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
  }
  else if (num == 8){ //segments ABCDEFG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[3], LOW);
    digitalWrite(pins[4], LOW);
    digitalWrite(pins[5], LOW);
    digitalWrite(pins[6], LOW);
  }
  else if (num == 9){ //segments ABCFG
    digitalWrite(pins[0], LOW);
    digitalWrite(pins[1], LOW);
    digitalWrite(pins[2], LOW);
    digitalWrite(pins[5], LOW);
    digitalWrite(pins[6], LOW);
  }
}