Скачать или смотреть How to Create a Class in Dart or Flutter Correctly

Learn how to effectively create a class in Dart or Flutter with proper constructors, private properties, and methods to manage data.
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How to Create a Class in Dart or Flutter Correctly

Creating classes in Dart or Flutter can seem daunting, especially if you’re new to object-oriented programming. If you've been asking yourself how to properly set up a class with private properties, constructors, getters, setters, and methods, you're not alone. In this guide, we will dive into the correct way to create a class in Dart, covering essential concepts and best practices along the way.

The Problem: Class Structure and Construction

Our main goal is to create a class named Actividad that will encapsulate the properties and methods we want. The initial attempt presented raised several questions about constructors and the concept of required parameters:

How do we define a constructor correctly?

What is the difference between @ required and required?

How can we improve our class design?

Let’s explore how to efficiently set up our class.

The Solution: Refined Class Structure

Here’s how we can create the Actividad class in a way that adheres to best practices in Dart.

Step 1: Define the Class and Properties

To define the class Actividad, we start by declaring it along with its properties. While initially, private properties were used (prefixed with an underscore), Dart also allows for public properties while maintaining clean code. Here’s the revised class:

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Step 2: Constructors and Required Parameters

In Dart nowadays, the required keyword specifies that a parameter must have a value provided when calling a constructor. This is a strong compile-time check that can help catch errors early on.

In the constructor, you directly assign the parameters using this for more concise syntax:

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Step 3: Methods for Data Manipulation

To further enhance our class, we can create methods that manipulate or represent the data. For example, we could create a method to convert our object's properties into a map for easier storage or transmission:

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Step 4: String Representation

Implementing a toString method allows us to provide a string representation of our objects, which is useful for debugging:

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Putting It All Together

Combining all the elements, our complete Actividad class looks like this:

[[See Video to Reveal this Text or Code Snippet]]

Key Takeaways

Avoid Unnecessary Setters and Getters: Unless you need to perform specific actions, it’s often cleaner to use public fields.

Immutability: Consider using final for properties where applicable to create immutable objects.

Required Parameters: Use required, not @ required, for mandatory constructor parameters in newer Dart versions to ensure compile-time checks.

By following these guidelines, you can create robust classes in Dart and Flutter that are easy to manage and extend. Happy coding!