// declare constant
const int switchPin = 8;

// declare variables
int switchState = 0;
int prevSwitchState = 0;
unsigned long previousTime = 0;// positive variable 32 bit,  can count up to 4,294,967,295. will hold the time the LED was last changed
int led =2 ;// will be used to count which LED is the next one to be turned on. start out with pin 2
long interval = 1000;// interval between each LED turning on
//*************************************************************************
void setup() {
  Serial.begin(9600);// open serial port, 9600 bits per second
  for (int x = 2; x < 8; x++) {// LEDs connected to digital 2 - 7 
    pinMode(x, OUTPUT);// declare LED pins as OUTPUT
  }
  pinMode(switchPin, INPUT);// declare Switch pin as an INPUT
}//************************************************************************
void loop() {
  unsigned long currentTime = millis();// get the amount of time the Arduino has been running and store it in a local variable 
  if (currentTime - previousTime > interval) {
    previousTime = currentTime;
    digitalWrite(led, HIGH);
    led++; 
    if (led == 7) {// to check if the LED on pin 7 is turned on
    }
  }
  switchState = digitalRead(switchPin);// read the switch value into the switchState variable
  Serial.println(switchState);// print the switchState variable
  if (switchState != prevSwitchState) {//  checks to see if switchState does not equal prevSwitchState
    for (int x = 2; x < 8; x++) {
      digitalWrite(x, LOW);// if they are different, turn the all LEDs off
    }
    led = 2;// return the led variable to the first pin
    previousTime = currentTime;// reset the timer for the LEDs by seting previousTime to currentTime
  }
  prevSwitchState = switchState;// save the switch state in prevSwitchState , so you can compare it to the value you get for switchState in the next loop()
}