where to declare variables in flutter code example

Example 1: flutter variables

int num = 78;
String name = 'John Roberts';
bool yesorno = true;

Example 2: data types in flutter

main(List<String> args) {
  int number = 42;
  String name = 'Gurleen Sethi';
  double salary = 150300.56;
  bool isDoorOpen = true;
}