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遍歷map

sys htm shm key .com ext hashmap iter system

public static void main(String[] args) {


Map<String, String> map = new HashMap<String, String>();
map.put("1", "value1");
map.put("2", "value2");
map.put("3", "value3");

//第一種:普遍使用,二次取值
System.out.println("通過Map.keySet遍歷key和value:");

  for(String key : map.keySet()){

    System.out.println("key="+key+"and value="+map.get(key));    

  }

//第二種
System.out.println("通過Map.entrySet使用iterator遍歷key和value:");

Iterator<Map.EntrySet<String, String>> it = map.entrySet().iterator();

  while(it.hasNext()){

      Map.EntrySet<String, String> entry = it.next();

      System.out.println("key="+entry.getKey()+"and value="+entry.getValue());

  }

//第三種:推薦,尤其是容量大時
System.out.println("通過Map.entrySet遍歷key和value");

  for(Map.Entry<String, String> entry:map.entrySet()){

      System.out.println("key="+entry.getKey+"and value="+entry.getValue);

  }

//第四種
System.out.println("通過Map.values()遍歷所有的value,但不能遍歷key");

  for(String v : map.values()){

    System.out.println("value="+v);

  }

轉:http://www.cnblogs.com/kristain/articles/2033566.html

遍歷map