How to convert Char to Int in Haskell?

Question

I need to convert a Char to an Int in Haskell? For example:

a = '\x2' -- a == 2
          -- type of a should be Char
b = charToInt a -- b == 2
                -- type of b should be Int

How can I achieve this?

Chris Schmich · Accepted Answer · 2011-03-08 00:19:04Z

30

You can use the ord function to convert a character to its integer (ordinal) representation.

chr goes the other direction.

> ord '\x2'
  => 2
> chr 97
  => 'a'
> ord (chr 42)
  => 42

answered Mar 8, 2011 at 0:13

Chris Schmich

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1 Comment

just to add, you have to import Char or import Data.Char in order to use those

augustss · Accepted Answer · 2011-03-08 05:35:03Z

5

You can use fromEnum or Data.Char.ord.

answered Mar 8, 2011 at 5:35

augustss

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(fromEnum 'x') - (fromEnum '0') == x

@jpredham We have digitToInt '9' from Data.Char for that exact puprose