Code:
#define IR 2    // digital pin input for ir sensor
int detection = HIGH;    // no obstacle
// array digital pin for: green led(3,4,5) - white led (6,7,8)- red led (9,10,11)
int LedPIN[] = {3, 4, 5, 6, 7, 8, 9, 10, 11};   
    pinMode(LedPIN[i], OUTPUT);   
  detection = digitalRead(IR);