//创建Map集合 Map<Integer,String> map=new TreeMap<>(); //添加元素 map.put(2021001, "刘备"); map.put(2021002, "关羽"); map.put(2021003, "张飞"); map.put(2021004, "诸葛亮"); 补充代码,分别使用三种方法(keySet()遍历、entrySet()遍历、迭代器遍历)遍历容器中的元素,输出显示到屏幕上
时间: 2023-05-29 10:01:52 浏览: 82
//使用keySet()遍历
System.out.println("使用keySet()遍历:");
Set<Integer> keys = map.keySet();
for(Integer key:keys){
String value = map.get(key);
System.out.println(key+":"+value);
}
//使用entrySet()遍历
System.out.println("使用entrySet()遍历:");
Set<Map.Entry<Integer,String>> entries = map.entrySet();
for(Map.Entry<Integer,String> entry:entries){
int key = entry.getKey();
String value = entry.getValue();
System.out.println(key+":"+value);
}
//使用迭代器遍历
System.out.println("使用迭代器遍历:");
Iterator<Map.Entry<Integer,String>> iterator = map.entrySet().iterator();
while(iterator.hasNext()){
Map.Entry<Integer,String> entry = iterator.next();
int key = entry.getKey();
String value = entry.getValue();
System.out.println(key+":"+value);
}