arduino/SizeOfTest/SizeOfTest.ino

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

  Serial.print("Size of int: ");
  Serial.println(sizeof(int));
  
  Serial.print("Size of long: ");
  Serial.println(sizeof(long));
  
  Serial.print("Size of float: ");
  Serial.println(sizeof(float));
  
  Serial.print("Size of bool: ");
  Serial.println(sizeof(bool));
}

void loop() {

}