Java Map 程序问题

Question

1.添加treeMap元素时 标红但不报错 能运行

2.自动生成时总把包也导进来 标红不报错
treeMap.entrySet().var

entry.iter

3.
entry.getKey() 标红不报错 但entry.getValue不标红

源代码：

package map;

import java.util.Comparator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * @Date 2023/3/13 16:33
 */
public class TestTreeMap {
    public static void main(String[] args) {
        Comparator<Student> com=new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                int n1=o1.name.compareTo(o2.name);
                int n2=o1.age-o2.age;
                return n1==0?n2:n1;
            }
        };

        TreeMap<Student,String> treeMap=new TreeMap<Student, String>();
        Student s1=new Student("Neo",18);
        Student s2=new Student("Will",19);
        Student s3=new Student("Mike",15);

        //1.添加
        treeMap.put(s1,"北京");
        treeMap.put(s2,"上海");
        treeMap.put(s3,"天津");
        System.out.println("元素个数："+treeMap.size());
        System.out.println(treeMap);

        //2.删除
        treeMap.remove(new Student("Will",19));
        System.out.println(treeMap);

        //3.遍历
        //3.1entrySet()
        Set<Map.Entry<Student, String>> entries = treeMap.entrySet();
        for (Map.Entry<Student, String> entry : entries) {
            System.out.println(entry.getKey()+"---"+entry.getValue());
        }
        //3.2keySet()
        Set<Student> keys = treeMap.keySet();
        for (Student key : keys) {
            System.out.println(key+"---"+treeMap.get(key));
        }

    }
     static class Student implements Comparable<Student>{
        private String name;
        private int age;

        public Student(String name, int age) {
            this.name = name;
            this.age = age;
        }

        @Override
        public String toString() {
            return "Student{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    '}';
        }


         @Override
         public int compareTo(Student o) {
             int n1=this.name.compareTo(o.name);
             int n2=this.age-o.age;
             return n1==0?n2:n1;
         }
     }
}

Answer 1

编辑器的问题吧，啥编辑器呢，这种问题确实奇诡，都没人回答。。。