Haskell: Converting Int to String

问题

I know you can convert a String to an number with read:

Prelude> read "3" :: Int
3
Prelude> read "3" :: Double 
3.0

But how do you grab the String representation of an Int value?

回答1:

The opposite of read is show.

Prelude> show 3
"3"

Prelude> read $ show 3 :: Int
3

回答2:

An example based on Chuck's answer:

myIntToStr :: Int -> String
myIntToStr x
    | x < 3     = show x ++ " is less than three"
    | otherwise = "normal"

Note that without the show the third line will not compile.

回答3:

Anyone who is just starting with Haskell and trying to print an Int, use:

module Lib
    ( someFunc
    ) where

someFunc :: IO ()
x = 123
someFunc = putStrLn (show x)

来源：https://stackoverflow.com/questions/2784271/haskell-converting-int-to-string