如何遍历map<String,ArrayList<String>>这个数据结构呢 - 编程论坛

#2

y10222078202016-04-27 14:48

set<string> keys = ArrayList<String>.keySet();

然后用foreach方法遍历

新手班门弄斧，大神可以指教

#3

franksking2016-04-27 14:50

回复 2楼 y1022207820

Map <String, ArrayList> map = new HashMap <String, ArrayList>();
Set<String> keys = map.keySet();
Iterator<String> iterator = keys.iterator();
while(iterator.hasNext()) {
    String key = iterator.next();
    ArrayList arrayList = map.get(key);
    for(Object o : arrayList) {
        ...
    }
}
在网上查到的

#4

DriveK2016-04-27 20:31

@Test
public void testList(){
    String s="name";
    ArrayList<String> list=new ArrayList<String>();
    list.add("zhangsan");

        Map<String, ArrayList<String>> map=new HashMap<String, ArrayList<String>>();
        map.put(s, list);
        Set<Map.Entry<String, ArrayList<String>>> set=map.entrySet();
    //增强for  实现了Iterable接口集合都可以用
    for(Map.Entry<String, ArrayList<String>> entry:set){
    String s1=entry.getKey();
    ArrayList<String> list1=entry.getValue();
    System.out.println(s+"................"+list1.get(0));
    }
}

其实有什么不懂的，都能百度到，度娘很强大