Anonymous and Nested Function
Explore how to define and use anonymous functions, closures, and nested functions in Dart to write concise, modular code. Understand function scope, lexical capturing, and how to encapsulate logic effectively within other functions.
Anonymous functions
In programming, literals are fixed values written directly into the source code, such as the integer 5 or the string 'hello'. We use literals directly without needing to assign them a name.
We can apply this same concept to functions. Sometimes we only need a function's logic for a single, temporary operation. Naming the function becomes an unnecessary step. Dart provides a solution through anonymous functions. These are functions defined without a name, allowing us to pass them directly as data.
Syntax for anonymous functions
We define an anonymous function by providing a parameter list followed by a function body. We can use a block body with a return statement, or we can use the arrow syntax for a single expression.
(parameterList) {// block bodyreturn value;}(parameterList) => expression; // arrow syntax
When we pass anonymous ...