import 'dart:html'; void main() { querySelector("#sample_text_id") ..text = "Click me!" ..onClick.listen(reverseText); } void reverseText(MouseEvent event) { var text = querySelector("#sample_text_id").text; var buffer = new StringBuffer(); for (int i = text.length - 1; i >= 0; i--) { buffer.write(text[i]); } querySelector("#sample_text_id").text = buffer.toString(); }