// 2009 mlab.uiah.fi/paja
// Understanding functions

int val1Int;
int val2Int;

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


void loop(){
  readSensor1(3);
  
  val2Int = readSensor2(4);
  Serial.print("funcaion readSensor2: ");
  Serial.print(val2Int);
  
  Serial.println();
  delay(3000);
}

void readSensor1(int calib){  // function retun datatype
// Void means that the function returns nothing to the function from 
// which it was called. 
// Variables in brackets are called arguments. The argments are 
// the value which is passed from the function from which it was called.
// Arguments are regarded as variables, therefore datatype need to be defined.
// 
// an anatomy of function
// datatype function(datatype argument, datatype argument, ...){
//   statement;
// }
  int x;
  x = 10 * calib;
  
  Serial.print("funcaion readSensor1: ");
  Serial.print(x);
  Serial.println();
}

int readSensor2(int calib){
  // When function is declared with other than void, 
  // the function can return a value to the function from which it was called.
  // Return indicate the value. The value must be the same datatype as defined 
  // in the function declaration.
  int x;
  x = 10 * calib;
  return x;
}