Thank you (GrahamD) for raising this issue and thank you (JetFly) for providing these example test cases.

I've added them to the kata, with the addition of a couple that require the user to return "1 year".

tldr: U can't say that table is ordered, or the result is ordered(unless it's specified to order it).

You can always order finite set, as ordering require relation, and it is always possible to make relation between all objects in finite set.
Set of possible relations between elements of finite amount of sets is a carthesian product of those finite amount of sets,
relation is element of this set. In this case, we can simply tell that any result is ordered by relation x1x2...xn-1xn, where x~y means x is in relation with y.

More, ordering in sql makes preassumption that we want order result by '>' relation, or '<' in case of descending.
However, if we don't specify ordering, result of query should be treated as SET, same as tables in database, which means result is always UNORDERED (Disordered? It sounds like it has mental problems :D) unless we specify to order it somehow.

As usual, my English grammar is always terrible. :(
如同往常一样，我的英文语法总是很糟糕。[郁闷]
So I'm willing to accept all the suggestions for improving English grammar. ^_^
所以我愿意接受一切关于英语语法的改进建议。 [开心]
As you said, I want to keep the neat x and y format. :]
如你所言，我想要保持整洁的 x and y 格式。[迷之微笑]
So I decided to take your last suggestion: material7 or material8(at least one, or both) must be selected :)
所以我决定采用你最后的建议:材料7或材料8（至少一个）必须选取 [微笑]
Apologize to the 160 warriors who were misled by my description(even though they finally got the right answer ;-))
向被我的描述误导的160位勇士道歉（尽管他们克服重重困难最终得到了正确答案[抛媚眼]）

Solemnly Declare:

The above statements were generated by language translation software. If there is grammatical error, I do not bear any legal responsibility. :D
声明：以上言论是经过语言翻译软件生成的。如果存在语法错误，本人不承担任何法律责任。[咧嘴]
If there is any ambiguity, please use Chinese semantics as the standard. :P
如有歧义，请以中文语义为准。[吐舌头]
I reserve the final right to interpret the Chinese text. :)
我保留对中文文本的最终解释权。[微笑]

It is not selected at least once, because we're not selecting them multiple times.

The kata is asking if you can select a set of materials from the list at once.

So must be selected at least one makes sense. It's just, as myjinxin often does, not very grammatically correct (the correct grammar would be at least one of material7 and material8 must be selected).

I don't know why all of you are suggesting irrelevant edits that doesn't touch the core problem ;-)

I think you need to revisit the definition of at least one ;-)

Yes :)

It's just a 7kyu, no need to over-think or over-complicate it ;-)

Yes, but it's also hard to reveal more without completely spoiling the kata itself.

I guess you can think of it like this: you have a deck of already shuffled cards. How do you make it in total disorder?

Even if there is no order, it's still possible to test it ;-)

Hint: it has to do with statistics and distributions.

Well, obviously the rows are ordered by something. The task asks you to make the numbers (which are already ordered in their column) unordered.

And the only way to make something unordered is to make it impossible to find any order within it ;-)

As you can see, 118 people already solved this kata so I don't think your question is actually a question to most people ;-)

There is only one way to make already ordered things unordered, and there is no ambiguity.

(Also, you can always do an identity select to see the table contents. Why are you even asking for it in the first place?)

description updated

Assert.AreEqual("You are 17 year(s) old.", AgeDiff.CalculateAge(2003, 2020));
Assert.AreEqual("You were born this very year!", AgeDiff.CalculateAge(2003, 2003));
Assert.AreEqual("You will be born in 17 year(s).", AgeDiff.CalculateAge(2020, 2003));

//Remade, try this.

Thanks!

Maybe you will like these ones also: https://www.codewars.com/collections/dinglemouse

:-)

Fair enough, I updated the description :)