How to concatenate two integers in Haskell

Haskell is a statically typed, functional, and concurrent programming language with a dynamic range of packages.

We might come across situations entailing the concatenation of two integer values. In this scenario, we can use the following methods:

  • Concatenating integers as strings

  • Concatenating integers as integers

To concatenate two integer values in Haskell, the easiest way will be to convert both values to a string and then concatenate them using the Haskell concatenation operators.

This process involves:

  • The method show used to convert an int value to string.
    The syntax of this method is: show n, where n represents the integer value to be converted.

  • The operator (<> or ++) used for concatenating the converted string values, as follows: result = s1 <> s2 or result = s1 ++ s2

Let's go through the following examples for a better understanding of these methods:

Concatenating integers as strings

This example illustrates how to concatenate two integer values and return a string output:

concatTwoIntToStr :: Int -> Int -> String
concatTwoIntToStr n1 n2 = ((show n1) ++ (show n2))
main :: IO ()
main = do
   let a = 42
       b = 45
   putStr "The result is: "
   let result = concatTwoIntToStr a b
   putStr (result)

Let's go over the code widget above:

  • Lines 1–2: Define a function that accepts two integer parameters, convert them to a string using the show method, then concatenate them and return back the concatenated value.

  • Lines 6–7: Declare two integer values.

  • Line 9: Invoke the function concatTwoIntToStr previously defined and store the result in a variable named result.

  • Line 10: Print out the string result.

Concatenating integers as integers

This example illustrates how to concatenate two integer values and return an integer value as output:

concatTwoIntToInt :: Int -> Int -> Int
concatTwoIntToInt n1 n2 = read ((show n1) ++ (show n2))
main :: IO ()
main = do
   let a = 42
       b = 45
   putStr "The result is: "
   let result = concatTwoIntToInt a b
   putStr (show result)

Let's go over the code widget above:

  • Lines 1–2: Define a function that accepts two integer parameters, convert them to a string using the show method, then concatenate them and return back the concatenated value. The read function is applied to convert the result from a string to a number.

  • Lines 6–7: Declare two integer values.

  • Line 9: Invoke the function concatTwoIntToInt previously defined and store the result in a variable named result.

  • Line 10: Print out the result while using the show method to convert the integer result to a string.

Free AI Mock Interviews
Coding Interview
Coding PatternsFree Interview
Gain insights and practical experience with coding patterns through targeted MCQs and coding problems, designed to match and challenge your expertise level.
System Design
You TubeFree Interview
Learn to design a video streaming platform like YouTube by tackling functional and non-functional requirements, core components, and high-level to detailed design challenges.

Free Resources

Copyright ©2025 Educative, Inc. All rights reserved