int s[6]; //this is for storing analog value of each sensor
int thresould[6] = {512,512,512,512,512,512}; //this is the mid value
int base[6]={1,2,4,8,16,32}; //this is for binary to decimal conversion
int sensor; //this is to store final value after binary conversion

void setup() {
  Serial.begin(9600);
}

void loop() {
  reading();
  show_the_value(); //this is to check the sensor reading in serial monitor. comment this out if you make the robot line follow because this code slows the robot
  
}
void reading() {
  sensor = 0; //this is to refresh initial value
  for (int i = 0 ; i < 6 ; i++) {
    s[i] = analogRead(i);
    (s[i] > thresould[i]) ? s[i] = 1 : s[i] = 0; //conditional statement. this is to convert analog value to digital. if you want to see real analog value, then comment it. but for line follow, you must uncomment it.
    sensor += s[i] * base[i]; //this is to merge all 6 values and imagine them in a single binary number. then i converted it into decimal number to use as final value. better search about base convertion
  }
}

void show_the_value() {
  for (int i = 5 ; i >= 0 ; i++)
    Serial.print(String(s[i], 10) + " ");
  Serial.print(sensor);
  Serial.println();
}