int segmentPins[] = {2, 3, 4, 5, 6, 7, 8}; 
int commonCathodePin = 9; 

int digit [10] = { 
	B00111111, //0
	B00000110, //1
	B01011011, //2
	B01001111, //3
	B01100110, //4               I reversed this part of the code because bitRead
	B01101101, //5                 function reads from LSB to MSB. In this case,
	B01111101, //6              the LSB of the array "segmentPins" is 2 or A, while 
	B00000111, //7               the MSB is 8 or G. In order to display the correct
	B01111111, //8                  number, reversing it from the original code 
	B01101111  //9               (i.e. B11000000 it wont display 0) is essential.
}; 

void setup() { 
	for (int i = 0; i < 7; i++) { 
		pinMode(segmentPins[i], OUTPUT); 
	}
	pinMode(commonCathodePin, OUTPUT); 
} 

void loop() { 
	for (int i=0; i<10; i++) { 
		displayDigit(i); 
		delay(1000); 
	} 
} 

void displayDigit(int number) { 
	digitalWrite(commonCathodePin, LOW); 
	for (int i = 0; i <7; i++) { 
		digitalWrite(segmentPins[i], bitRead(digit[number], i)); 
	}
	digitalWrite(commonCathodePin, HIGH);
}