常见的Map的遍历方式

Map的遍历

• entrySet遍历

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

// 向map中添加一些元素
map.put(1, 100);
map.put(2, 200);
map.put(3, 300);

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

• keySet遍历

for(Integer key: map.keySet()){
    Integer value = map.get(key);
    System.out.println("key:" + key + "value:" + value);
}

• valuses遍历

for(Integer value: map.valuses()){
    Integer value = map.get(key);
    System.out.println("value:" + value);
}

• Iterator遍历

Iterator<Map.Entry<Integer, Integer>> iterator= map.entrySet().iterator();
while(iterator.hasNext()){
    Map.Entry<Integer, Integer> entry = itreator.next();
    Integer key = entry.getKey();
    Integer value = entry.getValue();
    System.out.println("key:" + key + "value:" + value);
}