java遍历HashMap

Java遍历HashMap有多种方法，以下是其中的几种：

1.使用Iterator遍历HashMap

Map<String, Integer> map = new HashMap<>();
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);
}

2.使用For-Each循环遍历HashMap

Map<String, Integer> map = new HashMap<>();
for (Map.Entry<String, Integer> entry : map.entrySet()) {
    String key = entry.getKey();
    Integer value = entry.getValue();
    System.out.println("key:" + key + ", value:" + value);
}

3.使用Lambda表达式遍历HashMap

Map<String, Integer> map = new HashMap<>();
map.forEach((key, value) -> System.out.println("key:" + key + ", value:" + value));

4.使用Stream API遍历HashMap

Map<String, Integer> map = new HashMap<>();
map.entrySet().stream().forEach(entry -> System.out.println("key:" + entry.getKey() + ", value:" + entry.getValue()));