如何为对象进行排序

方法很简单
第一步：对象需要实现 Comparable
第二部：需要重写 compareTo方法
直接上代码

public class Student implements Comparable<Student> {

    private String name;
    private int score;

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

    // 定义Student的compareTo函数
    // 如果分数相等，则按照名字的字母序排序
    // 如果分数不等，则分数高的靠前
    @Override
    public int compareTo(Student that) {

        if( this.score < that.score )
            return -1;
        else if( this.score > that.score )
            return 1;
        else // this.score == that.score
            return this.name.compareTo(that.name);
    }

    // 定义Student实例的打印输出方式
    @Override
    public String toString() {
        return "Student: " + this.name + " " + Integer.toString( this.score );
    }
}

先按照学生的成绩 score进行排序，再按照名字进行排序

public static void main(String[] args) {
        Student[] d = new Student[4];
        d[0] = new Student("D",90);
        d[1] = new Student("C",100);
        d[2] = new Student("B",95);
        d[3] = new Student("A",95);
        SortEnum.SELECTSORT.sort(d);
        for( int i = 0 ; i < d.length ; i ++ )
            System.out.println(d[i]);
    }

结果

image.png