Dart and Flutter

Learn that Flutter uses the Dart language and why this pair was chosen.

The Dart language

Flutter apps are written in Dart. Dart is also an object-oriented, statically typed language developed by Google. During development a JIT compiler enables hot reload in seconds; for release builds an AOT compiler compiles directly to machine code.

String isim = 'Ada';   // cannot be null
String? takmaAd;         // can be null

Sound null safety

Dart's sound null safety separates nullable values from non-nullable ones at the type level. Adding ? after a type allows null; without it the compiler rejects null assignments. Null reference errors are caught before they crash the app.

int yas = 25;     // cannot be null
int? puan;         // can be null
puan = null;       // valid

Exercise Null safety variables

In main, declare int yas = 25. Declare String? takmaAd and assign null. Then print yas and takmaAd with print.

Show example solution

void main() {
  int yas = 25;
  String? takmaAd;
  takmaAd = null;
  print(yas);
  print(takmaAd);
}

Test yourself

Why did Flutter choose Dart?
- It does not support classes or inheritance
- It requires no compilation step
- JIT for hot reload and AOT for fast release builds
- It was designed only for web pages
Show answer

JIT for hot reload and AOT for fast release builds — Dart's JIT and AOT modes give Flutter fast development and efficient release builds.
Nullable type
```
int____ sayac;
```
Show answer
```
int? sayac;
```
Dart and Flutter

JIT

Enables hot reload in development
AOT

Compiles release builds to machine code
Sound null safety

Prevents null reference errors
Dart

Flutter's programming language

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