有没有一种更快的方法来检查列表中的某个项目是否大于，小于或等于某个数字？

Question

Is there a faster way to check if an item in a list is greater than, less than, equal to a certain number?

Or you just have to loop through it? Im just curious if there are pre-built functions for this.

Example:

List contains 5, 5, 10, 15, 15, 20.

I want to check if how many items are actually >= 5. So the answer is 6. If I want to check >= 15, the answer would be 3.

Answer 1

step 1 : sort the list
step 2 : find the index for desired element
step 3 : print length-index

Answer 2

I don't see any such methods in the documentation , so I would say NO . You have to iterate through the List. If it is sorted, you can do binary search for faster results.

Answer 3

您需要循环检查每个元素的条件。

Answer 4

Are you trying to sort? If you are dealing with arrays you can use Arrays.sort() else if you are dealing with collections you can use Collections.sort()

Answer 5

No there is no pre-built function afaik. If your list items are not order critical(ie you are not making any priority list or LIFO/FIFO), you can improve the searching through sorting list before finding the element.

Answer 6

您可以对列表进行排序，然后只需将其第一个和最后一个元素与数字进行比较。

Answer 7

That is why I am asking a question if there is such method that currently exists within the Collection.

There is no such method in the standard collection APIs.

Write a loop. It should be quicker code and test a 5 line method to do this than scouring the internet for a 3rd party library. And your code will most likely be faster ... and certainly no slower.

Just do it. (I'd write the code for you myself, but it sounds like you need the practice ...)