“`
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.TreeMap;
public class AppOfMap {
public static void main(String[] args) {
Map<Integer, Person> people = new LinkedHashMap<>();
Map<Person, String> people2 = new TreeMap<>();
people.put(8, new Person("Sarah", 4));
people.put(3, new Person("Mark", 44));
for (Integer key : people.keySet())
System.out.println(people.get(key));
people2.put(new Person("Sarah", 4), "ad");
people2.put(new Person("John", 44), "ac");
System.out.println(people2);
for (Person key : people2.keySet())
System.out.println(people2.get(key));
}
}
“`Map所装的内容是可以很方便的排序的,而Map与List的最大不同在于可以根据一个类的排序方式,来输出另一个类