Kata

I recently passed this in Rust so here's my attempt at an aswer.

The solution setup has given us a macro like such:

#[macro_export]
macro_rules! fizz_buzz_custom {
    () => { fizz_buzz_custom_solver("Fizz", "Buzz", 3, 5) };
    ($str_one:expr) => { fizz_buzz_custom_solver($str_one, "Buzz", 3, 5) };
    ($str_one:expr, $str_two:expr) => { fizz_buzz_custom_solver($str_one, $str_two, 3, 5) };
    ($str_one:expr, $str_two:expr, $num_one:expr) => { fizz_buzz_custom_solver($str_one, $str_two, $num_one, 5) };
    ($str_one:expr, $str_two:expr, $num_one:expr, $num_two:expr) => { fizz_buzz_custom_solver($str_one, $str_two, $num_one, $num_two) };
}

The tests call this macro. This macro prevides default values to function paramaters. So your function will allways get all four arguments. Code as if you always get valid values for string_one, string_two, num_one and num_two. The macro will handle giving the default values when the argument is missing.

I don't know if any of that makes any sense, but I solved this by just coding the missing function as it is given.

🛄

Thank you for your reply.

I guess it's me who don't understand how macros work. If I look at the line from the description

fizz_buzz_custom("What's ", "up?", 3, 7)[80] # returns "What's " (81 is divisible by 3)

when I look at the macro it calls my function with

fizz_buzz_custom_solver("What's ", "up?", 3, 7)

what does the [80] then mean in this context? From looking at the expected return I see I'm not to return for all the numbers from 1 to 100, but rather the number after the bracketed one I have no clue how/where I'm to find this parameter.

The output of your function is Vec<String>, one can index a vector like this:

let my_vector: Vec<i32> = Vec::new();
my_vector.push(0);
my_vector.push(69);
my_vector.push(1337);
if my_vector[1] == 69 {
  println!("my_vector at index 1 was 69, the 2nd element was indexed");
}

so fizz_buzz_custom("What's ", "up?", 3, 7)[80] computes the whole vector, but indexes it with 80, so the 81th element of the resulting vector is retrieved.

You are right. I had to read troubleshoot document and reread instructions. I didn't see the words "Fizz", "Buzz", 3, and 5 by default!

This worked perfectly, thank you! Could you elaborate on why I shouldn't use global variables?

They keep their values between tests for instance.

Yes I've done a lot of testing with my own code and with test data (my own and kata provided)

output below for TEST and ATTEMPT

Time: 868ms Passed: 11 Failed: 100 Exit Code: 1
Test Results:
 Example Tests
 should return an array counting from 1 to 100, when the number is not divisible by 3 or 5 (2 of 2 Assertions)
 should return 'FizzBuzz' at the index of a number divisible by 3 and 5
 should return 'Fizz' at the index of a number divisible by 3
 should return 'Buzz' at the index of a number divisible by 5
 should return custom strings in place of 'Fizz' and 'Buzz' if two strings are passed as parameters (3 of 3 Assertions)
 should return custom strings at custom divisions if 2 strings and 2 intgers are passed as parameters (3 of 3 Assertions)
Completed in 0.85ms
 Random Tests
 Random Test Cases
[1, 2, 'Fizz', 4, 'Buzz', 'Fizz', 7, 8, 'Fizz', 'Buzz', 11, 'Fizz', 13, 14, 'FizzBuzz', 16, 17, 'Fizz', 19, 'Buzz', 'Fizz', 22, 23, 'Fizz', 'Buzz', 26, 'Fizz', 28, 29, 'FizzBuzz', 31, 32, 'Fizz', 34, 'Buzz', 'Fizz', 37, 38, 'Fizz', 'Buzz', 41, 'Fizz', 43, 44, 'FizzBuzz', 46, 47, 'Fizz', 49, 'Buzz', 'Fizz', 52, 53, 'Fizz', 'Buzz', 56, 'Fizz', 58, 59, 'FizzBuzz', 61, 62, 'Fizz', 64, 'Buzz', 'Fizz', 67, 68, 'Fizz', 'Buzz', 71, 'Fizz', 73, 74, 'FizzBuzz', 76, 77, 'Fizz', 79, 'Buzz', 'Fizz', 82, 83, 'Fizz', 'Buzz', 86, 'Fizz', 88, 89, 'FizzBuzz', 91, 92, 'Fizz', 94, 'Buzz', 'Fizz', 97, 98, 'Fizz', 'Buzz'] should equal [1, 2, 'Fizz', 4, 'Buzz', 'Fizz', 7, 8, 'Fizz', 'Buzz', 11, 'Fizz', 13, 14, 'FizzBuzz', 16, 17, 'Fizz', 19, 'Buzz', 'Fizz', 22, 23, 'Fizz', 'Buzz', 26, 'Fizz', 28, 29, 'FizzBuzz', 31, 32, 'Fizz', 34, 'Buzz', 'Fizz', 37, 38, 'Fizz', 'Buzz', 41, 'Fizz', 43, 44, 'FizzBuzz', 46, 47, 'Fizz', 49, 'Buzz', 'Fizz', 52, 53, 'Fizz', 'Buzz', 56, 'Fizz', 58, 59, 'FizzBuzz', 61, 62, 'Fizz', 64, 'Buzz', 'Fizz', 67, 68, 'Fizz', 'Buzz', 71, 'Fizz', 73, 74, 'FizzBuzz', 76, 77, 'Fizz', 79, 'Buzz', 'Fizz', 82, 83, 'Fizz', 'Buzz', 86, 'Fizz', 88, 89, 'FizzBuzz', 91, 92, 'Fizz', 94, 'Buzz', 'Fizz', 97, 98, 'Fizz', 'Buzz']
[1, 2, '!,.', 4, 'Op\x0cf', '!,.', 7, 8, '!,.', 'Op\x0cf', 11, '!,.', 13, 14, '!,.Op\x0cf', 16, 17, '!,.', 19, 'Op\x0cf', '!,.', 22, 23, '!,.', 'Op\x0cf', 26, '!,.', 28, 29, '!,.Op\x0cf', 31, 32, '!,.', 34, 'Op\x0cf', '!,.', 37, 38, '!,.', 'Op\x0cf', 41, '!,.', 43, 44, '!,.Op\x0cf', 46, 47, '!,.', 49, 'Op\x0cf', '!,.', 52, 53, '!,.', 'Op\x0cf', 56, '!,.', 58, 59, '!,.Op\x0cf', 61, 62, '!,.', 64, 'Op\x0cf', '!,.', 67, 68, '!,.', 'Op\x0cf', 71, '!,.', 73, 74, '!,.Op\x0cf', 76, 77, '!,.', 79, 'Op\x0cf', '!,.', 82, 83, '!,.', 'Op\x0cf', 86, '!,.', 88, 89, '!,.Op\x0cf', 91, 92, '!,.', 94, 'Op\x0cf', '!,.', 97, 98, '!,.', 'Op\x0cf'] should equal [1, 2, '!,.', 4, 'Op\x0cf', '!,.', 7, 8, '!,.', 'Op\x0cf', 11, '!,.', 13, 14, '!,.Op\x0cf', 16, 17, '!,.', 19, 'Op\x0cf', '!,.', 22, 23, '!,.', 'Op\x0cf', 26, '!,.', 28, 29, '!,.Op\x0cf', 31, 32, '!,.', 34, 'Op\x0cf', '!,.', 37, 38, '!,.', 'Op\x0cf', 41, '!,.', 43, 44, '!,.Op\x0cf', 46, 47, '!,.', 49, 'Op\x0cf', '!,.', 52, 53, '!,.', 'Op\x0cf', 56, '!,.', 58, 59, '!,.Op\x0cf', 61, 62, '!,.', 64, 'Op\x0cf', '!,.', 67, 68, '!,.', 'Op\x0cf', 71, '!,.', 73, 74, '!,.Op\x0cf', 76, 77, '!,.', 79, 'Op\x0cf', '!,.', 82, 83, '!,.', 'Op\x0cf', 86, '!,.', 88, 89, '!,.Op\x0cf', 91, 92, '!,.', 94, 'Op\x0cf', '!,.', 97, 98, '!,.', 'Op\x0cf']
[1, 2, '`', 4, '\x0b>%G%Njj', '`', 7, 8, '`', '\x0b>%G%Njj', 11, '`', 13, 14, '`\x0b>%G%Njj', 16, 17, '`', 19, '\x0b>%G%Njj', '`', 22, 23, '`', '\x0b>%G%Njj', 26, '`', 28, 29, '`\x0b>%G%Njj', 31, 32, '`', 34, '\x0b>%G%Njj', '`', 37, 38, '`', '\x0b>%G%Njj', 41, '`', 43, 44, '`\x0b>%G%Njj', 46, 47, '`', 49, '\x0b>%G%Njj', '`', 52, 53, '`', '\x0b>%G%Njj', 56, '`', 58, 59, '`\x0b>%G%Njj', 61, 62, '`', 64, '\x0b>%G%Njj', '`', 67, 68, '`', '\x0b>%G%Njj', 71, '`', 73, 74, '`\x0b>%G%Njj', 76, 77, '`', 79, '\x0b>%G%Njj', '`', 82, 83, '`', '\x0b>%G%Njj', 86, '`', 88, 89, '`\x0b>%G%Njj', 91, 92, '`', 94, '\x0b>%G%Njj', '`', 97, 98, '`', '\x0b>%G%Njj'] should equal [1, 2, '`', 4, '\x0b>%G%Njj', '`', 7, 8, '`', '\x0b>%G%Njj', 11, '`', 13, 14, '`\x0b>%G%Njj', 16, 17, '`', 19, '\x0b>%G%Njj', '`', 22, 23, '`', '\x0b>%G%Njj', 26, '`', 28, 29, '`\x0b>%G%Njj', 31, 32, '`', 34, '\x0b>%G%Njj', '`', 37, 38, '`', '\x0b>%G%Njj', 41, '`', 43, 44, '`\x0b>%G%Njj', 46, 47, '`', 49, '\x0b>%G%Njj', '`', 52, 53, '`', '\x0b>%G%Njj', 56, '`', 58, 59, '`\x0b>%G%Njj', 61, 62, '`', 64, '\x0b>%G%Njj', '`', 67, 68, '`', '\x0b>%G%Njj', 71, '`', 73, 74, '`\x0b>%G%Njj', 76, 77, '`', 79, '\x0b>%G%Njj', '`', 82, 83, '`', '\x0b>%G%Njj', 86, '`', 88, 89, '`\x0b>%G%Njj', 91, 92, '`', 94, '\x0b>%G%Njj', '`', 97, 98, '`', '\x0b>%G%Njj']

It would be better if you post your code because I passed the kata in Python without problems, check the link in Blind4Basics's post about markdown and mark your post as having spoiler content.

@bbirkinbine: you should not post solutions on publicly available repos, it's forbidden :/

Wasn't aware, changed that repo to private.

I'm not sure what is confusing about it. If the first two arguments have default values of "Fizz" and "Buzz" then passing in "Hey" and 8 would replace them. This will work for weakly typed languages, but not for strongly typed ones.

It will also be different if you are using named parameters versus not, which the original kata languages did not.

To answer your question though, "Say the function call was fizz_buzz_custom('Hey', 8). Then is string_two still "buzz" and num_two still 5?" the kata description states:

• The 1st and 2nd arguments are strings, "Fizz" and "Buzz" by default;
• The 3rd and 4th argyments are integers, 3 and 5 by default.

So, order matters... at least with the languages the kata originally supported.

I originally left out sample tests, as I felt you should be writing your own, if you want them.

Thoughts?

That's never a good idea for regular kata. It's gonna cause newcomers to raise issues where they could be easily avoided. All other languages so far seem to have sample tests too, making JS an outlier. I'm not sure if sample tests is a requirement (formally), but nowadays you won't see a kata get approved without them.

Hi,

see above, plz.

The function returns an array.

fizz_buzz_custom.class
=> Array

Not array index but values of array.

Please read the docs in the detailed answer provided to your previous "gripe" with this kata. If your code submissions passes, you'll have a solution to view (which you currently do not).

There is nothing missing from the description, examples, or test cases that would prevent you from being able to complete this kata.

Best of luck.

When I first wrote this, I probably listened to more feedback than I should have.

Q: Does that mean an array of length 100? Or does it mean an array whose elements are numbers from 1 to 100? A: I believe this at one point said, "an array whose elements are numbers from 1 to 100."

Q: What does "the index of the array for the number" mean? I assume it just means that if x is the array, then x[i] should be equal to 'Fizz' if i is divisible by 3, etc. But the examples don't show that. It seems to show that if i+1 is divisible by 3, ... A: If the number in the returned array is divisible by n.

Q: I'm not sure what it means to use defaults for the values. A: The Mozilla Developer Network has some nice documents explaining default arguments (parameters)

Q: So are we supposed to write our own test? A: If you'd like to test, yes. There are docs for CodeWars testing.

Q: I have no idea what the program is supposed to do, so how could I possibly write a test to see if it does it correctly? A: All the required information is included in the description and the examples. I suggest focusing on the examples, as they explicitly state exactly what the program should do.

Try not to get frustrated. Perhaps try the original FizzBuzz kata first, then come back to this one.

Please let me know if you have any further questions.

But the instructions say that under certain circumstances, the value of the area should be the string "Fizz" or "Buzz" or "FizzBuzz". Those are not numbers from 1 to 100. My question about default values is that the instructions don't say what the arguments are used for. They only say what the function is supposed to do if there are no arguments.

Here's what I think you're asking for: fizzBuzzCustom(stringOne, stringTwo, numOne, numTwo) returns the result of starting with the array [1, 2, ..., 100], and replacing each number in the array by stringOne if it is divisible by numOne (but not divisible by numTwo), replacing it by stringTwo if it is divisible by numTwo (but not numOne), and replacing it by the concatenation of stringOne and stringTwo if it's divisible by both. If a number in the array is divisible by neither numOne nor numTwo, leave it unchanged.

If fewer than 4 arguments are supplied, use the default values of "Fizz" for stringOne, "Buzz" for stringTWo, 3 for numOne and 5 for numTwo.

• Should the array alement always be a number if the index is not divisible by 3 or 5? Create a method/function that returns an array of numbers from 1 to 100.

• When should only one string be included when two are passed as function arguments? I'm not quite sure what you're asking. When should only one string be included where?

The last two sentences in the description explain the order of arguments and their default values: The first and second arguments are strings, which should be 'Fizz' and 'Buzz' by default. The third and fourth arguments are integers and and should be 3 and 5 by default.

Please let me know if you feel you need further clarification that isn't explicit in the definition and/or the examples.

If I'm understanding correctly, there would never just be an array of numbers. The array consists of numbers and strings. If the index is divisible by 3 or five, there will be a string. If it isn't, then there will be a number. The array will contain 100 items. Is my understanding correct?

I see now why I was confused on the string to use when strings are passed as arguments. In the instructions, an example test passes 'Hey' and 'There' as arguments. Then, coincidentally, the full suite test has a test that returns 'HeyThere'. Because we're not provided with the suite tests, I can only assume that 'HeyThere' was passed as the first string argument and that this was not a result of concatanating 'Hey' and 'There'. Is this correct?

Which language?

Javascript

Good catch. I don't seem to be able to edit the kata. Allow collaborators is checked though, so if you're able to, please feel free.

The numbers determine which numbers in the array returned have been replaced by the words, based on divisibility. If no arguments are given, the defaults are equivalent to fizz_buzz_custom('Fizz', 'Buzz', 3, 5).

In the examples given, fizz_buzz_custom[44] returns "FizzBuzz" because the 45th element of an array of numbers from 1 to 100 is 45, and 45 is divisible by both of the default numbers (3 and 5).

If we pass in different arguments, for example fizz_buzz_custom("What's ", "up?", 3, 7)[2], this should return the 3rd element in the array of 1 to 100, where numbers in that array which are divisible by 3 have been replaced by "What's ", numbers in that array which are divisible by 7 are replaced by "up?", and numbers which are divisible by both are replaced with "What's up?". Since the 3rd element in an array of 1 through 100 is 3, which is divisible by 3 (the 3rd argument), this will return "What's ".

Does that help to clarify?

That really helped me, Thanks!

Hi kparekh01,

The square-bracket notation is the index of the array that the fizz_buzz_custom method returns.

So, for example, if I have an array, letters = ["a", "b", "c"], I can call letters[1] which will return "b". If I have a method called give_me_letters that returns an array of letters, such as:

def give_me_letters
  ["a", "b", "c"]
end

Then, I can treat the method give_me_letters the same way, as it returns the same array. So, give_me_letters[1] will return "b".

This is unrelated to passing custom numbers into the method as arguments which are used for the range. I hope it helps to answer your question, without being a spoiler.

Gotchya, thanks for making it clear.

Hi pgrennin,

The description did go through some changes early on, as per user feedback.

Would you care to offer a more descriptive criticism that may help us understand which part(s) of the description you are struggling with?

Oh hey, didn't know it was updated. I was unclear that the first and second string parameters are supposed to replace fizz and buzz.

glad i'm not the only one.

Ok, so it's just a bog standard fizzbuzz function. It's the examples that make it so confusing. I still can't get it to work - I'm getting 'Unknown error' I try to submit.

Do you have spaces between operators in your code? I kept getting "Unknown error" until I changed a bit of code from "i - 1" to "i-1". I have no idea why (Javascript quirk, Codewars quirk, or some other quirk).

This should be fixed now. Sorry for the inconvenience.

Thank you! wthit56 gave some invaluable feedback which definitely helped clarify the description!

Cheers,

I still find it very confusing, but I won't skip it.

Hi,

Thanks for the feeback!

I rewrote parts of the description. Let me know if that helps the readability or if it still needs some reworking.

Cheers

Saying an array of FizzBuzz and then describing it is still an odd way of putting things. You could just say "Write a function that returns an array. The values in the array should number from 1 to 100. If the number is divisible by the aNumber, the value should be aString. Same for bNumber and bString. If the number is divisible by both aNumber and bNumber, the value should be aString, with bString added onto the end." This adequately describes the expected result and how it should be constructed.

Don't use terms like "a FizzBuzz"; unless you already know what that is, it only serves to confuse the reader.

Also, you could give the names of arguments as shown in the stub solution. This will help the coder understand which arguments go where. Also, you could change the names of these arguments to better describe what they represent. aNumber aString bNumber bString might be a good option. Also, putting them in this order can make it easier to associate the two values for each term.

You're getting there, though. ^^

Right! I was totally assuming that everyone would be familiar with FizzBuzz, but I suppose that won't always be the case.

I've made some changes based on your suggestions. Let me know what you think, and thanks so much for the great feedback.

Cheers,

Cool. That's much better.

I would tweak it to not use "Fizz" and "Buzz" in the explanation at all, though. Also, using 3 and 5 to describe the algorithm is confusing, as those values may not be used at all. Instead, describe the arguments, with their names, and use those to describe the functionality.

Also:

• 'Fizz' and 'Buzz' by default isn't very clear. Say that the first two arguments, ("name of first argument" and "name of second argument") should be strings. If they are not provided, you should use "Fizz" and "Buzz" as their values, respectively.
• Same goes for the other arguments. Be as explicit as possible so that there can be no ambiguity as to what you mean.

I've added an example to hopefully make it clearer that 'Fizz', 'Buzz', 3, and 5 are the intended default arguments.

fizzBuzzCustom[44]             // returns 'FizzBuzz'

Of course, I happen to know what I intended before even creating this so your feedback is invaluable. Do you think this example makes it explicit enough, or would rewording/additional explanation make this less ambiguous?

I think explicit would be better, I'm afraid. Also, because arrays use zero-based indices, the examples are going to be pretty hard to understand no matter what you do. Maybe have fizzBuzzCustom[44] // (the number 45) returns 'FizzBuzz' (45 is divisible by 3 and 5) or something?

I really like this suggestion, and have added that to the examples.

I also tried rewording the description to make it more explicit.

Thanks again for all the great suggestions!

Let me know what you think.

Cheers,

Cool. I would also add the actual number that would have gone there, to be clear what is going on. But it's not completely necessary, I guess.

Also, fizzBuzzCustom[15] is still incorrect.

I'd say you still need an arguments listing. Give us the names of the arguments; this will link up the values with the parameters in the reader's head.

Also, should be Fizz and Buzz by default is confusing. It implies that the argument values provided will be Fizz and Buzz, if nothing else. But this is something the coder needs to do, so explicitly say something like "if aString is not provided, you should use 'Fizz' instead", and so on.

Hi OverZealous,

Thank you for the feedback. I haven't been able to find this test for "Happy", "Cow", 13, 27. Maybe I am missing something?

Hi OverZealous,

Thank you! I was looking at the Ruby, and didn't see it at first. I actually had 5 and 3 hard coded in my solution, and somehow the other tests didn't fail!

Updated.

Awesome!

Updated, thanks!

Thanks again for the always excellent and helpful feedback mlabrum. I think we finally have this one ready.

Cheers,

Thanks for the feedback, I think I've fixed the problem. Please try again, and sorry for any frustration.

Cheers,

For the first failure message, the problem is the number associated with fizz\_buzz\_custom[89] is 90 (since we're counting from 1), which is divisible by 15. Therefore, the value of fizz\_buzz\_custom[89] should be "FizzBuzz" instead of "Buzz". I think the other incorrect failure messages are similar small errors in the expectations.

I had a problem with my original solution where I had + instead of &&, which was giving me the wrong test cases, but I have since resolved this. I believe it should work now as expected.

I still got an error :

Test::Error: expected: fizz_buzz_custom('lol', 'dude')[92] to return 'dude', instead got: lol

93 is supposed to be divisible by 3, then the first word (lol) should be used right ?

Yes, you're absolutely right. My problem was in the solution I had something like 93 % (3 && 5) instead of 93 % (3 * 5). This should now be resolved.

Still wrong. 93 is not divible by 5, so only lol not loldude.

Maybe I didn't publish the change? Not sure, but I believe this should be resolved now. I've just re-published.

I just realized the problem. I had 5, 3 instead of 3, 5 in my original solution. Thank you very much for the feedback. I'll be more careful with my next Kata before publishing.

Thank you for the feedback :)

Nope, we gone from : Test::Error: expected: fizz_buzz_custom('lol', 'dude')[92] to return 'dude', instead got: lol to : Test::Error: expected: fizz_buzz_custom('lol', 'dude')[92] to return 'loldude', instead got: lol

Your test is still wrong.

Yes, I just fixed the test failure messages. I hope this finally works!

Sorry for any frustration and thank you so much for your feedback.

Cheers

Thank you for the feedback,

Your test cases showed me I had some problems with my code, and I refactored.

Sorry for any frustration, and thanks so much.

Cheers,

Yes, you're totally right!

I updated the tests to give more meaningful messages, and fixed the counter to start from 1 rather than 0.

Thanks so much for the feedback!