readingsaverages.java

Java经典例程 从外国一大学计算机教授出版物下载的代码 经典

import javagently.*;

class ReadingsAverages {

  /* Averaging readings (Display version)  J M Bishop May 2000
   * -----------------------------------
   *
   * Works out the average of readings within a certain range
   * Illustrates the if-statement
   */

  Display d = new Display ("Averaging readings");

  ReadingsAverages () {

    double total = 0;
    double reading;
    int min, max;
    int n;
    boolean done = false;
    String status;

    d.prompt("Minimum",0);
    d.prompt("Maximum",100);
    d.ready("Press ready when min and max adjusted");
    min = d.getInt("Minimum");
    max = d.getInt("Maximum");
    d.println("Min is "+min+" and max is "+max);
    d.prompt("Next reading",0);
    d.prompt("Finished?","No");
    d.println("Press ready after entering each reading");
    d.println("Enter Yes when finished");
    for (n = 0; !done;) {
      d.ready();
      reading = d.getDouble("Next reading");
      d.print ("  " + reading);
      if (reading >= min & reading <= max) {
        total += reading;
        n++;
        d.print("K");
      }
      else {
        d.print("X");
      }
      status = d.getString("Finished?");
      done = status.equals("Yes");
    }
    d.println("\n Average "+" for "+n+" readings is "+
      Stream.format(total/n,8,3));
  }

  public static void main (String [] args) {
    new ReadingsAverages ();
  }
}