Java遍历Map集合的方法(最新推荐)

Map<String, Integer> map = new HashMap<>();  
map.put("one", 1);  
map.put("two", 2);  
map.put("three", 3);  
 
for (String key : map.keySet()) {  
    Integer value = map.get(key);  
    System.out.println("Key: " + key + ", Value: " + value);  
}

Map<String, Integer> map = new HashMap<>();  
map.put("one", 1);  
map.put("two", 2);  
map.put("three", 3);  
for (Map.Entry<String, Integer> entry : map.entrySet()) {  
    String key = entry.getKey();  
    Integer value = entry.getValue();  
    System.out.println("Key: " + key + ", Value: " + value);  
}

Map<String, Integer> map = new HashMap<>();  
map.put("one", 1);  
map.put("two", 2);  
map.put("three", 3);  
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet().iterator();  
while (iterator.hasNext()) {  
    Map.Entry<String, Integer> entry = iterator.next();  
    String key = entry.getKey();  
    Integer value = entry.getValue();  
    System.out.println("Key: " + key + ", Value: " + value);  
}

Map<String, Integer> map = new HashMap<>();  
map.put("one", 1);  
map.put("two", 2);  
map.put("three", 3);  
map.forEach((key, value) -> {  
    System.out.println("Key: " + key + ", Value: " + value);  
});

import java.util.HashMap;  
import java.util.Map;  
public class MapExample {  
    public static void main(String[] args) {  
        // 创建一个HashMap实例  
        Map<String, Integer> map = new HashMap<>();  
        // 向Map中添加键值对  
        map.put("one", 1);  
        map.put("two", 2);  
        map.put("three", 3);  
        // 遍历Map的键（keySet）  
        for (String key : map.keySet()) {  
            System.out.println("Key: " + key + ", Value: " + map.get(key));  
        }  
        // 遍历Map的键值对（entrySet）  
        for (Map.Entry<String, Integer> entry : map.entrySet()) {  
            System.out.println("Key: " + entry.getKey() + ", Value: " + entry.getValue());  
        }  
        // 通过键检索值  
        int value = map.get("two");  
        System.out.println("Value for 'two': " + value);  
        // 检查Map中是否包含某个键  
        boolean containsKey = map.containsKey("one");  
        System.out.println("Map contains 'one': " + containsKey);  
        // 删除键值对  
        map.remove("one");  
        System.out.println("After removing 'one': " + map);  
    }  
}