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Flutter for Beginners

You're reading from   Flutter for Beginners An introductory guide to building cross-platform mobile applications with Flutter 2.5 and Dart

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Product type Paperback
Published in Oct 2021
Last Updated in Oct 2021
Publisher Packt
ISBN-13 9781800565999
Length 370 pages
Edition 2nd Edition
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Authors (2):
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Thomas Bailey Thomas Bailey
Author Profile Icon Thomas Bailey
Thomas Bailey
Alessandro Biessek Alessandro Biessek
Author Profile Icon Alessandro Biessek
Alessandro Biessek
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Table of Contents (18) Chapters Close

Preface 1. Section 1: Introduction to Flutter and Dart
2. Chapter 1: An Introduction to Flutter FREE CHAPTER 3. Chapter 2: An Introduction to Dart 4. Chapter 3: Flutter versus Other Frameworks 5. Chapter 4: Dart Classes and Constructs 6. Section 2: The Flutter User Interface – Everything Is a Widget
7. Chapter 5: Widgets – Building Layouts in Flutter 8. Chapter 6: Handling User Input and Gestures 9. Chapter 7: Routing – Navigating between Screens 10. Section 3: Developing Fully Featured Apps
11. Chapter 8: Plugins – What Are They and How Do I Use Them? 12. Chapter 9: Popular Third-Party Plugins 13. Chapter 10: Using Widget Manipulations and Animations 14. Section 4: Testing and App Release
15. Chapter 11: Testing and Debugging 16. Chapter 12: Releasing Your App to the World 17. Other Books You May Enjoy

Functions and methods

As we discussed previously, functions and methods are self-contained chunks of code that work on a specific task. Note that the syntax of methods and functions is identical, so where I refer to functions in this section, I am also referring to methods. Let's look at another example of a function, as follows:

String sayHello() { 
  return "Hello world!";
}

This sayHello function structure is very similar to the main function we explored previously but also includes a return type of String, so the function must have a return statement at the end that returns a value of the expected type. In this example, the function returns a String literal of "Hello world!". If the function could return a String literal or null then, as we saw in the Null safety section, we would mark the function's return type as String?.

Note that the function return type can be omitted because the Dart analyzer can infer the return type from...

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