本文介绍了如何在F#中编写Fizzbuzz的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我目前正在学习F#,并尝试了一个(非常)简单的FizzBu​​zz示例.

I am currently learning F# and have tried (an extremely) simple example of FizzBuzz.

这是我的最初尝试:

for x in 1..100 do
    if x % 3 = 0 && x % 5 = 0 then printfn "FizzBuzz"
    elif x % 3 = 0 then printfn "Fizz"
    elif x % 5 = 0 then printfn "Buzz"
    else printfn "%d" x

使用F#解决此问题,哪种解决方案可能更优雅/更简单/更好(解释原因)?

What solutions could be more elegant/simple/better (explaining why) using F# to solve this problem?

注意:FizzBu​​zz问题是通过数字1到100进行的,每3幅打印Fizz的倍数,每5幅打印Buzz的倍数,3和5幅打印FizzBu​​zz的每倍.否则,将显示简单的数字.

Note: The FizzBuzz problem is going through the numbers 1 to 100 and every multiple of 3 prints Fizz, every multiple of 5 prints Buzz, every multiple of both 3 AND 5 prints FizzBuzz. Otherwise, simple the number is displayed.

谢谢:)

推荐答案

我认为您已经有了最佳"解决方案.

I think you already have the "best" solution.

如果您想展示更多的功能/F#原理,则可以这样做

If you want to show off more functional/F#-isms, you could do e.g.

[1..100]
|> Seq.map (function
    | x when x%5=0 && x%3=0 -> "FizzBuzz"
    | x when x%3=0 -> "Fizz"
    | x when x%5=0 -> "Buzz"
    | x -> string x)
|> Seq.iter (printfn "%s")

并使用列表,序列,图,迭代,模式和部分应用程序.

and use lists, sequences, map, iter, patterns, and partial application.

[1..100]    // I am the list of numbers 1-100.
            // F# has immutable singly-linked lists.
            // List literals use square brackets.

|>          // I am the pipeline operator.
            // "x |> f" is just another way to write "f x".
            // It is a common idiom to "pipe" data through
            // a bunch of transformative functions.

   Seq.map  // "Seq" means "sequence", in F# such sequences
            // are just another name for IEnumerable<T>.
            // "map" is a function in the "Seq" module that
            // applies a function to every element of a
            // sequence, returning a new sequence of results.

           (function    // The function keyword is one way to
                        // write a lambda, it means the same
                        // thing as "fun z -> match z with".
                        // "fun" starts a lambda.
                        // "match expr with" starts a pattern
                        // match, that then has |cases.

    | x when x%5=0 && x%3=0
            // I'm a pattern.  The pattern is "x", which is
            // just an identifier pattern that matches any
            // value and binds the name (x) to that value.
            // The "when" clause is a guard - the pattern
            // will only match if the guard predicate is true.

                            -> "FizzBuzz"
                // After each pattern is "-> expr" which is
                // the thing evaluated if the pattern matches.
                // If this pattern matches, we return that
                // string literal "FizzBuzz".

    | x when x%3=0 -> "Fizz"
            // Patterns are evaluated in order, just like
            // if...elif...elif...else, which is why we did
            // the 'divisble-by-both' check first.

    | x when x%5=0 -> "Buzz"
    | x -> string x)
            // "string" is a function that converts its argument
            // to a string.  F# is statically-typed, so all the
            // patterns have to evaluate to the same type, so the
            // return value of the map call can be e.g. an
            // IEnumerable<string> (aka seq<string>).

|>          // Another pipeline; pipe the prior sequence into...

   Seq.iter // iter applies a function to every element of a
            // sequence, but the function should return "unit"
            // (like "void"), and iter itself returns unit.
            // Whereas sequences are lazy, "iter" will "force"
            // the sequence since it needs to apply the function
            // to each element only for its effects.

            (printfn "%s")
            // F# has type-safe printing; printfn "%s" expr
            // requires expr to have type string.  Usual kind of
            // %d for integers, etc.  Here we have partially
            // applied printfn, it's a function still expecting
            // the string, so this is a one-argument function
            // that is appropriate to hand to iter.  Hurrah!

这篇关于如何在F#中编写Fizzbuzz的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

07-07 22:26