Map 的 5 种遍历方式

Map 的 5 种遍历方式

强烈推荐 for-each + entrySet()遍历 和 lambda 表达式遍历 ，简洁又好用！！！

package com.maptest;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;public class MapTest {/*** Map 的 5 种遍历方式* @param args*/public static void main(String[] args) {Map<String, String> map = new HashMap<>();map.put("张三", "zhangsan");map.put("李四", "lisi");map.put("王五", "wangwu");// 1.for-each + keySet()遍历Set<String> keySet = map.keySet();for (String key : keySet) { //遍历keySystem.out.println(key + " :keySet: " + map.get(key));}// 2.for-each + entrySet()遍历（强烈推荐）for (Map.Entry<String, String> entry : map.entrySet()) {System.out.println(entry.getKey()+ " :entrySet: " + entry.getValue());}// 3.Iterator + entrySet()遍历Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();while (iterator.hasNext()) {Map.Entry<String, String> entry = iterator.next();System.out.println(entry.getKey() + " :Iterator: " + entry.getValue());}// 4.lambda 表达式遍历（强烈推荐）map.forEach((key, value) -> {System.out.println(key + " :lambda: " + value);});// 5.stream流 + entrySet 遍历map.entrySet().stream().forEach((Map.Entry<String, String> entry) -> {System.out.println(entry.getKey() + " :stream: " + entry.getValue());});}
}