Dart Libraries and visibility
Unlike Java, Dart doesn’t have the keywords public, protected, and private. If an identifier startswith an underscore _, it’s private to its library.
If you for example have class A in a separate library file (eg, other.dart), such as:
library other;
class A {
int _private = 0;
testA() {
print('int value: $_private'); // 0
_private = 5;
print('int value: $_private'); // 5
}
}and then import it into your main app, such as:
import 'other.dart';
void main() {
var b = new B();
b.testB();
}
class B extends A {
String _private;
testB() {
_private = 'Hello';
print('String value: $_private'); // Hello
testA();
print('String value: $_private'); // Hello
}
}You get the expected output:
String value: Hello
int value: 0
int value: 5
String value: Hello