sort后fill然后binarySearch

[jixixiaofeng]

import java.util.*;

public class TestArray{
public static void main(String[] args){
int[] num = {2,1,3,4,5};
Arrays.sort(num);
Arrays.fill(num,1,2,6);
System.out.println(Arrays.binarySearch(num,6));
}
}
应该显示是几呢？

我想应该是1，可输出是－6.为什么呢？

[若鱼1919]

int[] num = {2,1,3,4,5};
		Arrays.sort(num);
		System.out.println(Arrays.toString(num));
		Arrays.fill(num,1,2,6);
		System.out.println(Arrays.toString(num));
		//Searches the specified array of ints for the specified value using the binary search algorithm. 
		//The array must be sorted (as by the sort(int[]) method) prior to making this call. 
		//If it is not sorted, the results are undefined. 
		//If the array contains multiple elements with the specified value, 
		//there is no guarantee which one will be found.
		System.out.println(Arrays.binarySearch(num,6));

[Jlins]

+[Quote=引用 1 楼 goldenfish1919 的回复:]

Java code

int[] num = {2,1,3,4,5};
Arrays.sort(num);
System.out.println(Arrays.toString(num));
Arrays.fill(num,1,2,6);
System.out.println(Arrays.toString(num));
……
[/Quote]

[qian119110]

没有排序引起的混乱吧。

[djvfe]

Arrays.fill(num,1,2,6);是指吧num数组的第二个和第三个元素设置为6，完成后数组长度依然是5
好好看看api啊

[a411416948]

二分查找必先排序再查找
api原话
使用二分搜索法来搜索指定的 int 型数组，以获得指定的值。必须在进行此调用之前对数组进行排序（通过 sort(int[]) 方法）。如果没有对数组进行排序，则结果是不确定的。如果数组包含多个带有指定值的元素，则无法保证找到的是哪一个。