You, as a developer, want to provide in your library the possibility to add parameters that are not required to fill in. In Dart, you have some options. We will show all the options to accomplish this.
- [Narrator] Welcome to the video on optional…and formal parameters.…In the previous video we learned how to define…a factory constructor.…In this video we're going to take a look…at how to define parameters.…We will see what are the options…in defining parameters…in a method or constructor.…Next to normal parameters we have three other options.…The first one is used by a formal parameter.…A hash map filled with keys as strings…and values as objects.…The second one is the optional positioned parameters.…
In which the parameters are optional.…But the order is very important…and defines what the variables are.…The last one…optional named parameter…is also optional,…but the variables are defined by name…and can be given to the method in any order you like.…In our constructor factory we can add the parameters.…In our case we will add an option parameter.…This parameter has two properties.…Which is a number and damage.…
Since these are formal parameters,…you need to provide the variable option.…You will always need to check if the object is not null.…
Dart is a new open-source programming language for the web. It is a single language for both client and server that can be used to build large-scale web, server, and mobile applications. Stop solving new challenges with the same old tools—let Dart show you a whole new way! In this course, author Joris Hermans guides you into the wonderful world of web development with the dartlang programming language. By following along, you get a more mature sense of how to build a great application and see all the facets needed to reach that goal.
Learn the important language features of Dart, along with some advanced features such as mixins and null-aware operators. Later on, see how to use unit tests, work with browser APIs, and set up of a web server. Finally, take a look at Angular 2, a great front-end framework also built by Google.
This course provides you with everything you need to know to start or enhance your career in web development with Dart.
- Installing Dart
- Creating a basic web application with Dart
- Creating DOM interactions
- Creating classes and objects
- Implementing a library
- Using parameters, null-aware operators, and mixins
- Testing your code
- Setting up APIs
- Using Dart localStorage
- Working with AngularJS
- Troubleshooting Dart applications