#!/usr/local/bin/dart

void main() {

  var sb = new StringBuffer();
  sb..write('Hello ')
    ..write('world ')
    ..write('!');

  print(sb.toString());

  for (int i = 0; i < 5; i++) {
    print('Hello:  ${i}');
  }

  var arr = [];
  for (int i = 0; i < 10; i++) {
    arr.add(i);
  }
  print(arr);
  print(arr.join(':'));
}