Java_集合_ArrayLish Comparator比较排序 小笔记

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

class Teacher_Main {
    public static void main(String[] args) {

        ArrayList<Teacher> teacherList = new ArrayList<Teacher>();
        teacherList.add(new Teacher("污老湿", 35));
        teacherList.add(new Teacher("污老人", 15));
        teacherList.add(new Teacher("污小人", 7));
        teacherList.add(new Teacher("污大人", 99));
    
        
        Collections.sort(teacherList, new Comparator<Teacher>() {

            @Override
            public int compare(Teacher o1, Teacher o2) {
              if (o1.age > o2.age) {
                    return -1;
            } else if (o1.age < o2.age) {
                    return 1;
                }
                　　 return 0;
            }

        });        
        for (int i = 0; i < teacherList.size(); i++) {
           　　 Teacher teacher = teacherList.get(i);
            　　System.out.println(teacher);
            
        }
    }
}





class Teacher {
    public String name;
    public int age;

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

    @Override
    public String toString()/*转成字符串类型*/ {
        return name + ":" + +age;
    }

}