map练习 统计参数个数

package com.liangjing.set;import java.util.HashMap;import java.util.Iterator;import java.util.Set;public class ArgMap {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubHashMap map = new HashMap();for (int i = 0; i < args.length; i++) {             //循环遍历命令参数if (map.get(args[i]) == null) {             //将命令参数当作map集合的键,若取不到值,表示第一次遍历到,将参数当作键存入map,值设置为1map.put(args[i], new Integer(1));}else {                                       // Integer in = (Integer) map.get(args[i]); //否则,(不是第一次遍历)将原来键的值取出in = new Integer(in.intValue() + 1);     //次数加1map.put(args[i], in); //将原来的键和新值重新存入map}}Set s = map.keySet();for (Iterator iter = s.iterator(); iter.hasNext();) {String key = (String) iter.next();Integer value = (Integer) map.get(key);System.out.println(key + ":" + value);}}}

命令参数如下图

执行结果

hello:3123:2word:4