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Why you should use “const” constructor

Flutter development is based on the concept of Widget and on the creation of custom widgets to define the UI and behavior of your app. In this post, we’ll explore how using a const constructor for widgets can improve the performance of your Flutter app.

When you create a Flutter widget, the framework creates an instance of that widget and stores it in memory. If the widget is rebuilt (for example, if the underlying data changes), a new instance is created and the old one is discarded. This process can put a strain on the garbage collector, which is responsible for freeing up memory that is no longer in use.

To mitigate this strain, you can use a const constructor when creating your widgets. A const constructor is a special type of constructor that can only be used for creating instances of widgets that are immutable. In other words, the properties of the widget cannot change once it has been created.

By using a const constructor, you can let the Flutter framework know that the widget will not change, and therefore it can be stored in memory and reused without having to be reconstructed. This can have a significant impact on performance, especially in large or complex apps where many widgets are being rebuilt often.

In addition to improving the performance of the garbage collector, using a const constructor can also make your code more readable and maintainable thanks to the immutability of the widget.

To summarize, using a const constructor for widgets can significantly improve the performance of your Flutter app by reducing the amount of work required for the garbage collector. While the impact may not be noticeable in smaller apps, it can add up and make a big difference in larger or complex apps where views are frequently rebuilt.

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