package com.map;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Set;
public class HashMapTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
Hashtable<String, String> map = new Hashtable<>();
map.put("1", "2");
map.put("2", "3");
map.put("1", "4");
//1遍历hashtable获取key集合,根据key得到value
Enumeration<String> keys = map.keys();
while(keys.hasMoreElements()) {
String key = keys.nextElement();
String value = map.get(key);
System.out.println(key+"->"+value);
}
//2使用lambda表达式遍历hashtable
map.forEach((K,V)->System.out.println("key : " + K+ " value : " + V));
//3获取key集合的set视图根据key获取value
Set<String> set = map.keySet();
for (String key : set) {
System.out.println(key+"->"+map.get(key));
}
//4使用set视图得到迭代器进行遍历
Iterator<String> iterator = set.iterator();
for (String key : set) {
System.out.println(key+"--"+map.get(key));
}
//遍历hashtable值
Enumeration<String> elements = map.elements();
while(elements.hasMoreElements()) {
System.out.println(elements.nextElement());
}
}
}