Anushi1998

int a=1;

void main() {
  print(a);
  b();
  print(a);
}

void b() => a=2;

Anushi1998

void main() {
  ok();
  ok(x:null);
}

void ok({
  int x = 1,
}) {
  print(x);
}

Anushi1998

import 'dart:async';

void main() {
  bool a = false;
  
    StreamController controller = new StreamController(
        onCancel: () {
          a=true;
        });