J2SE Map集合的用法

1.声明一个map: Map map = new HashMap(); 

2.向map中放值,注意：map是key-value的形式存放的.如:

map.put(”sa”,”dd”);

3.从map中取值:String str = map.get(”sa”).toString();结果是:str = ”dd”;

4.遍历一个map，从中取得key 和value

JDK1.5

Map m = new HashMap(); 
for (Object o : map.keySet()) { 
map.get(o); 
}

JDK1.4

Map map = new HashMap() ; 
Iterator it = map.entrySet().iterator() ; 
while (it.hasNext()) 
{ 
Map.Entry entry = (Map.Entry) it.next() ; 
Object key = entry.getKey() ; 
Object value = entry.getValue() ; 
}