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Dart Strong Mode and ahead-of-time compilation

Dart is increasingly being used as a cross platform language, and on most of these platforms ahead-of-time (AOT) compilation is a key part of the development and deployment story.

The dynamic nature of Dart limits the effectiveness of ahead-of-time compilation, particularly as applications scale up in size. We therefore designed Strong Mode Dart to allow ahead-of-time compilers to generate better code by taking full advantage of the type information that programmers write.


While the initial goal of Strong Mode was to enable better ahead-of-time compilation, we've also seen strong uptake of Strong Mode from users who just like the stronger static checking because of it’s ability to make writing, reading, and refactoring Dart code more reliable.



The recent talk from the Dart Developer Summit gives an overview of Strong Mode: what it is, why having a sound type system is useful, and how it benefits developers by making their IDE experience better, and their errors more reliable.

If you’re curious to try out Dart Strong Mode, DartPad makes it really easy: simply tick the Strong mode box in the lower right corner.

Posted by Leaf Petersen, Software Engineer and Dart Strong Mode Aficionado

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We are constantly asking ourselves:
How do we make developers even more productive when writing Dart apps? We believe that a critical part of the answer to this question is to make strongmode – a sound static type system for Dart – the standard for all Dart developers.

Teams that use Dart to build apps like Soundtrap, AdWords, AdSense, and Greentea say they really enjoy using strong mode features, such as early error detection. In fact, teams that have switched completely to strong mode cite not only early error detection but also better code readability and maintainability as major benefits. We hear this both from small teams and – even more so – from large teams with hundreds of developers writing and maintaining millions of lines of Dart code. As Björn Sperber from Soundtrap says,
Strong mode and the smooth integration with IntelliJ is a joy to use and a huge improvement. If you’ve tried out Flutter, you’ve already used strong mode checks from the Dart analyzer.

Given the benefits …