Thermostat abdi - Hightechrobo bin

void setup() {
  Serial.begin(9600);
  sensors.begin();
  pinMode(heter,OUTPUT);
  pinMode(fan,OUTPUT);
  pinMode(7,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(10,OUTPUT);

}

void loop() {
  sensors.requestTemperatures();
  float temp = sensors.getTempCByIndex(0);
  int random = random(7,10);
  if (temp != DEVICE_DISCONNECTED_C)
  {  
    while(analogRead(LDR) < 400){
      digitalWrite(random, 1);
    }
    if(analogRead(LDR) >= 400){
      digitalWrite(7, 0);
      digitalWrite(8, 0);
      digitalWrite(9, 0);
      digitalWrite(10, 0);
    }
    if(temp <= 20){
      digitalWrite(fan, 0);
      digitalWrite(heter, 1);
    }
    if(temp >= 40){
      digitalWrite(fan, 1);
      digitalWrite(heter, 0);
    }
    if(temp < 40 && temp > 20){
      digitalWrite(fan, 0);
      digitalWrite(heter, 0);
    }
  }
  else
  {
    Serial.println("Data Error");
  }
}