Semantic portal
main()
void main() {
querySelector('#sample_text_id')
..text = 'Click me!'
..onClick.listen(reverseText);
}// Run the app like this: dart args.dart 1 test
void main(List<String> arguments) {
print(arguments);
assert(arguments.length == 2);
assert(int.parse(arguments[0]) == 1);
assert(arguments[1] == 'test');
}Every app must have a top-level main() function, which serves as the entrypoint to the app.
The main() function returns void and has an optional List<String> parameter for arguments.