example illustrates autoboxing and unboxing

 Design Patterns

Most developers claim to experience an epiphany reading this book. If you've never read the Design Patterns book then you have suffered a very serious gap in your programming education that should be remedied immediately.

 

The following example illustrates autoboxing and unboxing, along with generics and the for-each loop.

 

 

package test;

 

import java.util.*;

 

//Prints a frequency table of the words on the command line

public class Frequency {

 public static void main(String[] args) {

      Map<String, Integer> m = new TreeMap<String, Integer>();

      for (String word : args) {

          Integer freq = m.get(word);

          m.put(word, (freq == null ? 1 : freq + 1));

      }

      System.out.println(m);

 }

}

//这是计算输入的字符串,每一个词使用架频率.

//命令行输入:if it is to be it is up to me to do the watusi

//该结果应为:be=1, do=1, if=1, is=2, it=2, me=1, the=1, to=3, up=1, watusi=1