一、说明
1、 static void sort ( Object[ ] a ):
(1)要求对象数组的元素实现java.lang.Comparable接口,即支持比较大小。元素重写的int compareTo(Object obj)指定按照什么排序,就怎么排序
2、static void sort ( Object[ ] a , Comparator c):
(1)给对象数组传一个java.util.Comparator接口的实现类对象,重写的int compare(Object o1, Object o2)方法中指定排序的规则
public void test15() {
Student[] arr = new Student[3];
arr[0] = new Student(1,"张三",23,89);
arr[1] = new Student(2,"宋鑫",22,100);
arr[2] = new Student(3,"牛钰琪",20,90);
//按照年龄,年龄相同,就按照学号排序
Arrays.sort(arr, new Comparator(){
@Override
public int compare(Object o1, Object o2) {
Student s1 = (Student) o1;
Student s2 = (Student) o2;
int result = s1.getAge() - s2.getAge();
if(result != 0){
return result;
}
return s1.compareTo(s2);//Student类中实现的compareTo方法是按照学号排序
}
}
);
System.out.println(Arrays.toString(arr));
}