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ArrayList集合儲存學生並排序

package com.czie.iot1913.lps.genericityDemo.Collections;

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

/**
* @author [email protected]
* @date 2022-03-20 22:59
*/
public class ArrayTest01 {
public static void main(String[] args) {
//建立集合物件
ArrayList<Student> array = new ArrayList<Student>();
//建立學生物件
Student s1 = new Student("劉品水",21);
Student s2 = new Student("劉水",25);
Student s3 = new Student("b水",18);
Student s4 = new Student("a水",18);
//把學生新增到集合
array.add(s1);
array.add(s2);
array.add(s3);
array.add(s4);

//static <T> void sort(List<T> list, Comparator<? super T> c)
//根據指定的比較器指定的順序對指定的列表進行排序。

Collections.sort(array, new Comparator<Student>() {
@Override
public int compare(Student s1, Student s2) {
int num1=s1.getAge()-s2.getAge();
int num2=num1==0?s1.getName().compareTo(s2.getName()):num1;
return num2;
}
});
for (Student s:array){
System.out.println(s.getName()+","+s.getAge());
}



}
}


package com.czie.iot1913.lps.genericityDemo.Collections;

/**
* @author [email protected]
* @date 2022-03-20 22:59
*/
public class Student {
private String name;
private int age;

public Student() {
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

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