總共有三種方法
通過keySet()遍歷
for (String s:m.keySet()
) {
System.out.println(s+"======"+m.get(s));
}
通過 Map.Entry 遍歷
// 通過Map.entrySet()遍歷
System.out.println("通過Map.entrySet()遍歷");
for ( Map.Entry<String ,Integer> entry:map1.entrySet()
) {
System.out.println(entry.getKey()+"======"+entry.getValue());
}
// 使用迭代器遍歷
System.out.println("使用迭代器遍歷 Map.Entry");
Iterator<Map.Entry<String, Integer>> iterator = map1.entrySet().iterator();
while (iterator.hasNext()){
Map.Entry<String,Integer> entry = iterator.next();
System.out.println(entry.getKey()+"====="+entry.getValue());
}
遍歷所有的 value (只能遍歷所有的 value)
for (Integer i : map1.values()
) {
System.out.println(i);
}
附完整代碼:
public static void main(String[] args) {
Map<String,Integer> map = new HashMap<>();
map.put("1",1);
map.put("2",2);
map.put("3",3);
map.put("4",4);
Map<String,Integer> map1 = new HashMap<>();
map1.put("11",11);
map1.put("21",21);
map1.put("31",31);
map1.put("41",41);
List<Map> list = new ArrayList();
list.add(map);
list.add(map1);
System.out.println(list);
for (Map<String, Integer> m:list
) {
System.out.println("通過keySet()遍歷");
for (String s:m.keySet()
) {
System.out.println(s+"======"+m.get(s));
}
}
// 通過Map.entrySet()遍歷
System.out.println("通過Map.entrySet()遍歷");
for ( Map.Entry<String ,Integer> entry:map1.entrySet()
) {
System.out.println(entry.getKey()+"======"+entry.getValue());
}
// 使用迭代器遍歷
System.out.println("使用迭代器遍歷 Map.Entry");
Iterator<Map.Entry<String, Integer>> iterator = map1.entrySet().iterator();
while (iterator.hasNext()){
Map.Entry<String,Integer> entry = iterator.next();
System.out.println(entry.getKey()+"====="+entry.getValue());
}
// 遍歷所有的 value (只能遍歷所有的 value)
System.out.println("遍歷所有的value");
for (Integer i : map1.values()
) {
System.out.println(i);
}
}