// Recording weather information with a superclass (version~3)
// fig:recordings-super4

abstract class ARecording {
 int high;
 int today;
 int low; 

 ARecording(int high,int today,int low) {
  this.high = high;
  this.today = today;
  this.low = low;
 }

 int dHigh() { return this. high - this. today; }

 int dLow() { return this. today - this. low; }

 String asString() {
  return 
   String.valueOf(high).concat("-").concat(String.valueOf(low)).concat(this.unit());
 }

 abstract String unit(); 
}


class Temperature extends ARecording {
 Temperature(int high,int today,int low) { 
  super(high,today,low);
 }

 String unit() {
  return "F"; 
 }
}


class Pressure extends ARecording {
 Pressure(int high,int today,int low) { 
  super(high,today,low);
 }

 String unit() {
  return "hPa"; 
 }
}


class Examples {
  Pressure p1 = new Pressure(103289, 101325, 95839);
  Pressure p2 = new Pressure(102389, 102325, 100839);

  Temperature t1 = new Temperature(82, 78, 67);
  Temperature t2 = new Temperature(57, 48, 32);

  // tests for the method dHigh
  boolean testDHigh1 = p1.dHigh() == 1964;
  boolean testDHigh2 = p2.dHigh() == 64;

  boolean testDHigh3 = t1.dHigh() == 4;
  boolean testDHigh4 = t2.dHigh() == 9;

  // tests for the method dLow
  boolean testDLow1 = p1.dLow() == 5486;
  boolean testDLow2 = p2.dLow() == 1486;

  boolean testDLow3 = t1.dLow() == 11;
  boolean testDLow4 = t2.dLow() == 16;

  // test the method asString
  boolean testAsString1 = p1.asString().equals("103289-95839hPa");
  boolean testAsString2 = p2.asString().equals("102389-100839hPa");

  boolean testAsString3 = t1.asString().equals("82-67F");
  boolean testAsString4 = t2.asString().equals("57-32F");

}