Coding/Learn/haskell/haskell tuples
Learn Haskell & Pure Functional Programming
01.Introduction to Haskell & GHC
02.Syntax, Comments & Program Layout
03.Basic Types & Immutability
04.Arithmetic, Precedence & Infix Functions
05.Strings, Lists & the Cons Operator (:)
06.Booleans, Equality & Logical Operators
07.Conditional Expressions (if then else)
08.Function Guards (| condition = result)
09.Pattern Matching on Functions
10.Case Expressions (case of)
11.Local Bindings with let ... in
12.Auxiliary Bindings with where Clauses
13.Function Signatures & Referential Transparency
14.Currying & Partial Function Application
15.Anonymous Lambda Expressions (\x -> expr)
16.Higher-Order Functions: map, filter, foldl & foldr
17.Function Composition (.) & Application ($)
18.Recursion Patterns & Tail Recursion
19.Tuples & Pair Operations (fst, snd)
20.List Functions: head, tail, take, drop & null
21.Arithmetic Sequences & List Ranges
22.List Comprehensions
23.Zipping & Combining Lists (zip, zipWith)
24.Lazy Evaluation & Infinite Streams
25.Type Inference & Type Variables
26.Standard Typeclasses: Eq, Ord, Show & Num
27.Defining Custom Typeclasses & Instances
28.Type Synonyms (type) & newtype Wrappers
29.Algebraic Data Types (data ADT)
30.Record Syntax & Named Fields
31.The Maybe Type & Null Safety
32.The Either Type for Detailed Errors
33.Pattern Matching on Maybe & Either
34.Domain Errors & Validation Pipelines
35.Recursive Data Structures: Binary Trees
36.Strictness, seq & Bang Patterns (!)
37.The Functor Typeclass & fmap (<$>)
38.Applicative Functors: pure & (<*>)
39.The Monad Typeclass & Bind Operator (>>=)
40.Do Notation & Monadic Desugaring
41.The Three Monad Laws
42.Monadic Utilities: sequence, mapM, forM & when
43.The IO Monad & Pure/Impure Separation
44.File I/O: Reading & Writing Files
45.Modules, Exports & Qualified Imports
46.Monad Transformers: Reader, Writer & State
47.Concurrency, forkIO & MVars
48.Property-Based Testing with QuickCheck
49.Unit Testing & Test Suites (HUnit / Hspec)
50.Monadic Parsing & Parser Combinators
51.Production Architecture: Cabal & Stack
52.Comprehensive Functional Practice Challenges
53.Final Knowledge Assessment Quiz
54.Capstone Project: Domain Expression Evaluator & AST Engine
55.Verified Haskell Developer Certificate
Course Certificate0%

Complete all lessons to earn

LearnTuples & Pair Operations (fst, snd)
19 / 55 0%
Lesson 19 of 55
9 mins read

Tuples & Pair Operations (fst, snd)

PreviousNext Lesson
In Plain English

Unlike homogeneous lists, tuples have a fixed length and can contain elements of different types (e.g. (1, "Alice", True)). Pairs (2-tuples) feature helper functions fst and snd.

Deep Dive: How It Works

Tuple Types: (Int, String) is a 2-tuple. The type depends on both size and element types.

Pair Functions: fst (x, y) = x and snd (x, y) = y work exclusively on 2-tuples.

Pattern Matching: Destructure arbitrary tuples: (a, b, c) -> a + b + c.

PointCore Rules to Remember

Point star
Heterogeneous Types: Combine multiple different data types into a single fixed record.
Point star
fst and snd: Extract the first and second elements from 2-tuples.

Live Interactive Example

Hit Run Code to see it live
Tuples and Pattern Destructuring
Python 3.12
1
2
3
4
5
6
7
8
9
10
11
12
Output Console
Click "Run Code" to view the rendered output.
How it works: minMaxAvg returns a 3-tuple destructured into minVal, maxVal, avgVal.

Your Turn: Micro Challenge

No pressure! Edit the starter code below and test your solution with instant feedback.

Micro Exercise

Swap Pair Elements

  • PointDefine `swapPair (a, b) = (b, a)`.
  • PointPrint `"Swapped: "` followed by `show (swapPair (1, "two"))`.
1
2
3
4
5
6
7
Sandbox Output
Click "Run & Check" to test your solution.

Finished reading and practicing?

Mark this lesson as completed to update your course progress.

PreviousNext Lesson
Overview100 SheetLearnCertificates