LCD Custom characters

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Custom characters:
byte heart[8] = {
  B00000,
  B01010,
  B11111,
  B11111,
  B11111,
  B01110,
  B00100,
  B00000
};

byte smiley[8] = {
  B00000,
  B00000,
  B01010,
  B00000,
  B00000,
  B10001,
  B01110,
  B00000
};

byte armsDown[8] = {
  B00100,
  B01010,
  B00100,
  B00100,
  B01110,
  B10101,
  B00100,
  B01010
};

byte armsUp[8] = {
  B00100,
  B01010,
  B00100,
  B10101,
  B01110,
  B00100,
  B00100,
  B01010
};

void setup() {
  lcd.createChar(0, heart);
  lcd.createChar(1, smiley);
  lcd.createChar(2, armsDown);
  lcd.createChar(3, armsUp);

  lcd.begin(16, 2);
  lcd.print("I ");
  // When you use '0' character, you have to cast to argument as byte.
  lcd.write((byte)0);
  lcd.print(" Arduino! ");
  lcd.write(1);

}

void loop() {
  lcd.setCursor(4, 1);
  lcd.write(2);
  delay(500);
  lcd.setCursor(4, 1);
  lcd.write(3);
  delay(500);
}