Functions

1. Functions in codeLockedNamed, reusable blocks of code that take inputs (parameters) and produce outputs (return values).Opens after: Input and output
2. First-class functionsLockedFunctions are values like any other - they can be named, passed to other functions, returned and stored - which lets one function hold a pattern of work and take the details from outside.Opens after: Lists, Functions in code
3. RecursionLockedA function that solves a problem by calling itself on a smaller version of the same problem, until it reaches a base case.Opens after: Functions in code, Conditionals, Nested data
4. Return valuesLockedThe value a function hands back to the code that called it, with return, so its answer can be stored, added or passed on - unlike print, which only shows it on the screen.Opens after: Functions in code
5. ScopeLockedWhere in a program a name can be used - names made inside a function are local to it, so functions can't trip over each other's names.Opens after: Return values
6. DecompositionLockedSplitting a task into smaller named steps, each small enough to write and check on its own, so a big program reads as a story of calls.Opens after: Scope

Connections to other domains

• Functions in code leads to GoroutinesConcurrency
• Recursion leads to LoopsControl Flow
• Recursion needs ConditionalsControl Flow
• Recursion needs Nested dataData Structures
• Functions in code leads to PointersData Types
• Functions in code, depth 2 needs FunctionsAlgebra
• Functions in code needs Input and outputProgram Basics
• First-class functions leads to SortingAlgorithms
• Functions in code leads to ConcurrencyConcurrency
• Return values leads to BooleansControl Flow
• First-class functions leads to ComprehensionsData Structures
• Return values leads to NoneData Types
• Decomposition, depth 2 needs Classes and objectsObjects and Classes
• Decomposition, depth 2 needs TestingWriting Correct Code
• First-class functions needs ListsData Structures
• Functions in code leads to Classes and objectsObjects and Classes
• Functions in code leads to Modules and importsOrganizing Programs
• Functions in code leads to ExceptionsWriting Correct Code