All sample codes from this lesson:

********************************************************

WHILE introduction:

void setup() {
  // put your setup code here, to run once:
  pinMode (2,INPUT_PULLUP);
  Serial.begin(9600);

  while (digitalRead(2)==HIGH) 
  {
  Serial.println("Here I am, just a loopin!");
  } 
  Serial.println("I have now escaped out of the while loop");      
}

void loop() {
  // put your main code here, to run repeatedly:
 
}


********************************************************

FOR loop, example 1:

void setup() {
  // put your setup code here, to run once:
  pinMode (2,INPUT_PULLUP);
  pinMode (3,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int bright=0; bright <256; bright++){
    //this first loop increases the brightness of the LED until it hits maximum brightness
    analogWrite (3,bright);
    delay(10);
  }

  for (int bright=255; bright >=0; bright--){
    //this first loop decreases the brightness of the LED until it hits minimum brightness
    analogWrite (3,bright);
    delay(10);
  }
}


********************************************************

FOR loop, example 2:

void setup() {
  // put your setup code here, to run once:
  pinMode (2,INPUT_PULLUP);
  pinMode (3,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int bright=0; bright <256; bright=bright+51){
    //this first loop increases the brightness of the LED until it hits maximum brightness
    analogWrite (3,bright);
    delay(500);
  }

  for (int bright=255; bright >=0; bright=bright-51){
    //this first loop decreases the brightness of the LED until it hits minimum brightness
    analogWrite (3,bright);
    delay(500);
  }
}

********************************************************

FOR loop, example 3:

void setup() {
  // put your setup code here, to run once:
  pinMode (2,INPUT_PULLUP);
  pinMode (3,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int bright=0; bright <256; bright++){
    //this first loop increases the brightness of the LED until it hits maximum brightness
    analogWrite (3,bright);
    delay(500);
    bright=bright+51;
  }

  for (int bright=255; bright >=0; bright--){
    //this first loop decreases the brightness of the LED until it hits minimum brightness
    analogWrite (3,bright);
    delay(500);
    bright=bright-51;
  }
}


********************************************************

FOR loop, example 4:


void setup() {
  // put your setup code here, to run once:
  pinMode (2,INPUT_PULLUP);
  pinMode (3,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int bright=0; bright <256; bright++){
    //this first loop increases the brightness of the LED until it hits maximum brightness
    analogWrite (3,bright);
    delay(500);
    if (digitalRead(2)==LOW)
    {
      bright=bright+51;
    }
  }

  for (int bright=255; bright >=0; bright--){
    //this first loop decreases the brightness of the LED until it hits minimum brightness
    analogWrite (3,bright);
    delay(500);
    if (digitalRead(2)==LOW)
    {
      bright=bright-51;
    }
  }
}