Dart Chapter 4 of 15

Functions

Write reusable blocks of code: parameters, return values, arrow syntax, closures, higher-order functions and recursion.

A function is a named piece of code you can run whenever you need it. Functions let you write something once, test it once and use it everywhere.

Lessons in this chapter

1. Functions in Dart: Defining, Calling and Returning ValuesLearn how to define and call functions in Dart, pass arguments, return values, and understand void, scope and local functions.
2. Function Parameters in Dart: Positional, Named, Optional and DefaultMaster Dart function parameters: required positional, optional positional, named parameters, the required keyword and default values.
3. Arrow Functions in Dart (=> Syntax)Write short functions in Dart with the arrow syntax. Learn what => means, where it can be used and where a block body is needed.
4. Anonymous Functions and Closures in DartUnderstand anonymous functions (lambdas) in Dart, how to store functions in variables, and how closures remember values.
5. Higher-Order Functions in DartLearn higher-order functions in Dart: functions that take or return other functions, with map, where, reduce, fold and your own examples.
6. Recursion in Dart: Functions That Call ThemselvesLearn recursion in Dart with factorial, Fibonacci and sum examples. Understand base cases, the call stack and when to use a loop instead.
7. typedef in Dart: Naming Function and Other TypesUse typedef in Dart to give long function types and generic types a short, readable name. Includes practical callback examples.