java中map集合的用法

http://blog.csdn.net/ycyangcai/archive/2009/06/21/4285997.aspx

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

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Map m = new HashMap();

for (Object o : map.keySet()) {

map.get(o);

}

JDK1.4

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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() ;

}