Java代码如何迭代HashMap呢?

实现思路:
    方式1：
	   使用Java8的forEach
	方式2:
	   使用for循环,对HashMap进行迭代
	方式3:
	   使用map.entrySet().iterator()获取迭代器
	       然后迭代

//1.Java 8 forEach
Map<String, String> map = new HashMap<>();
map.forEach((key, value) -> System.out.println("[Key] : " + key + " [Value] : " + value));

//2. for循环遍历HashMap 
Map<String, String> map = new HashMap<>();
for (Map.Entry<String, String> entry : map.entrySet()) {
	System.out.println("[Key] : " + entry.getKey() + " [Value] : " + entry.getValue());
}

//3.经典迭代器
Map<String, String> map = new HashMap<>();  
Iterator iter = map.entrySet().iterator();
while (iter.hasNext()) {
	Map.Entry entry = (Map.Entry) iter.next();
	System.out.println("[Key] : " + entry.getKey() + " [Value] : " + entry.getValue());
}

 
package com.java265.calculator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
public class HashMapExample {
    public static void main(String[] args) {
 
        Map<String, Integer> map = new HashMap<>();
        map.put("java265.com-1",1);
        map.put("java265.com-2",2);
        map.put("java265.com-3",3);
 
        System.out.println("Java 8 forEach loop");
        map.forEach((key, value) -> System.out.println("[Key] : " + key + " [Value] : " + value));
 
        System.out.println("for entrySet()");
        for (Map.Entry<String, Integer> entry : map.entrySet()) {
            System.out.println("[Key] : " + entry.getKey() + " [Value] : " + entry.getValue());
        }
 
        System.out.println("Iterator");
        Iterator iter = map.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry entry = (Map.Entry) iter.next();
            System.out.println("[Key] : " + entry.getKey() + " [Value] : " + entry.getValue());
        }
    }
}