Future example

main.dart

import 'dart:async';
import 'dart:io';

void main(){
	print(imConnected());
}

imConnected() async {
  try {
    final result = await InternetAddress.lookup('google.com');
    if(result.isNotEmpty && result[0].rawAddress.isNotEmpty)
      return true;
    } on SocketException catch(_) {
    return false;
  }
}