PairTest2.java Source code

Introduction

Here is the source code for PairTest2.java

Source

/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.util.Calendar;
import java.util.GregorianCalendar;

/**
 * @version 1.00 2004-05-10
 * @author Cay Horstmann
 */
public class PairTest2 {
    public static void main(String[] args) {
        GregorianCalendar[] birthdays = { new GregorianCalendar(1906, Calendar.DECEMBER, 9), // G. Hopper
                new GregorianCalendar(1815, Calendar.DECEMBER, 10), // A. Lovelace
                new GregorianCalendar(1903, Calendar.DECEMBER, 3), // J. von Neumann
                new GregorianCalendar(1910, Calendar.JUNE, 22), // K. Zuse
        };
        Pair<GregorianCalendar> mm = ArrayAlg.minmax(birthdays);
        System.out.println("min = " + mm.getFirst().getTime());
        System.out.println("max = " + mm.getSecond().getTime());
    }
}

class ArrayAlg {
    /**
       Gets the minimum and maximum of an array of objects of type T.
       @param a an array of objects of type T
       @return a pair with the min and max value, or null if a is 
       null or empty
    */
    public static <T extends Comparable> Pair<T> minmax(T[] a) {
        if (a == null || a.length == 0)
            return null;
        T min = a[0];
        T max = a[0];
        for (int i = 1; i < a.length; i++) {
            if (min.compareTo(a[i]) > 0)
                min = a[i];
            if (max.compareTo(a[i]) < 0)
                max = a[i];
        }
        return new Pair<T>(min, max);
    }
}
/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @version 1.00 2004-05-10
 * @author Cay Horstmann
 */
class Pair<T> {
    public Pair() {
        first = null;
        second = null;
    }

    public Pair(T first, T second) {
        this.first = first;
        this.second = second;
    }

    public T getFirst() {
        return first;
    }

    public T getSecond() {
        return second;
    }

    public void setFirst(T newValue) {
        first = newValue;
    }

    public void setSecond(T newValue) {
        second = newValue;
    }

    private T first;
    private T second;
}