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@tomaszpolanski
Last active November 7, 2021 10:33
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Issue With dart null safety 1
class A {
A(this.text);
final String? text; // Final field
}
class B implements A {
bool _first = true;
@override
// Not final anymore
String? get text {
if (_first) {
_first = false;
// On the first call return null
return 'Some string';
} else {
// On the next calls return null
return null;
}
}
}
void main() {
final A example = B();
print(example.text); // Prints 'Some string'
print(example.text); // Prints null
}
void main() {
final A example = B();
if (example.text != null) {
print(example.text!.length);
}
}
final String? text;
@override
Widget build(BuildContext context) {
return Column(
children: [
if (text != null) Text(text!), // Won't compile without `!` in `text!`
],
);
}
final String? text;
@override
Widget build(BuildContext context) {
final _text = text;
return Column(
children: [
if (_text != null) Text(_text), // The `!` is not longer needed
],
);
}
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