myTestSort.java

## 程序功能： 实现sort接口

import java.math.BigDecimal;
import java.util.Arrays;

public class sortMyTest {
 public static void main(String[] args) {
 Person[] ps = new Person[] {
 new Person("Bob", 61.5),
 new Person("Alice", 61.2),
 new Person("Lily", 75),
 };
 Arrays.sort(ps);
 System.out.println(Arrays.toString(ps));
 }
}

class Person implements Comparable<Person> {
 String name;
 double score;
 Person(String name, double score) {
 this.name = name;
 this.score = score;
 }
 @Override
 public int compareTo(Person other) {
 //这里每次new两个对象，如果数据量大，肯定是慢的。
 BigDecimal a = new BigDecimal(this.score);
 BigDecimal b = new BigDecimal(other.score);
 return a.compareTo(b);
 }
 @Override
 public String toString() {
 return this.name + "," + this.score;
 }
}