WeatherMonitor.java

import java.io.*;
import java.util.Scanner;

public class WeatherMonitor {

    /*
    *   Program:    WeatherMonitor.java
    *   Purpose:    Read temperature data from file, show daily difference in temperature
    *   Creator:    Chris Clarke
    *   Created:    04.12.2014
    */

    /*  Note:       You need a text file called "weather.txt", containing the following:

                16.2 23.5 19.1 7.4 22.8 18.5 -1.8 14.9

    */

    public static void main(String[] args) throws IOException, FileNotFoundException {
        File f = new File("weather.txt");
        Scanner filescan = new Scanner(f);
        double oldTemp, newTemp=999;
        double change;
        boolean firstTime = true;

        while (filescan.hasNext()) {
            if (firstTime) {
                oldTemp = filescan.nextDouble();
                firstTime = false;
            } else {
                oldTemp = newTemp;
            } // if
            newTemp = filescan.nextDouble();
            change = newTemp - oldTemp;
            System.out.printf("%.1f to %.1f, change = %.1f%n",oldTemp,newTemp,change);
        } // while
    } // main()
} // class WeatherMonitor