public class MapLearn {
public static void main(String[] args) throws ParseException {
Map<String,String> map=new HashMap<>();
map.put("01", "01");
map.put("02", "02");
map.put("03", "03");
map.put("04", "04");
map.put("02", "055");//key值重复,会覆盖前一个
//把map中key保存到set中,然后根据获取set中的key值去取value
Set<String> keySet=map.keySet();
Iterator<String> iterator=keySet.iterator();
while(iterator.hasNext()){
String key=iterator.next();
System.out.println("Key:"+key);
String ss=map.get(key);
System.out.println("Value:"+ss);
}
//把map中key与value的关系保存到set中
Set<Map.Entry<String, String>> me=map.entrySet();
Iterator<Map.Entry<String, String>> iterator2=me.iterator();
while(iterator2.hasNext()){
Map.Entry<String, String> s=iterator2.next();
String key=s.getKey();
String value=s.getValue();
System.out.println(key+":"+value);
}
}
}
转载于:https://my.oschina.net/u/2416019/blog/626272