Dart: Scalable Application Development

Functions and closures in different scopes

I like Dart because everything is an object. Functions are first-class citizens because they support all the operations that are generally available to other types. This means each function have the following properties:

• They can be named by a variable
• They can be passed as an argument to a function
• They can be returned as the result of a function
• They can be stored in data structures
• They can be created in any scope

Let's see where and how can we use functions as usual or as first-class citizens.

Naming functions with a variable

Naming functions by variable means that we can create a reference to a function and assign it to a variable, as shown in the following code:

library function_var; // Returns sum of [a] ...