freq.java

初级学习资料必读本

import java.util.*;

public class Freq {
    private static final Integer ONE = new Integer(1);

    public static void main(String args[]) {
        Map m = new TreeMap();

        // Initialize frequency table from command line
        for (int i=0; i<args.length; i++) {
            Integer freq = (Integer) m.get(args[i]);
            m.put(args[i], (freq==null ? ONE :
                            new Integer(freq.intValue() + 1)));
        }

        System.out.println(m.size() + " distinct words detected:");
        System.out.println(m);
    }
}