如何在node.js中将数据转换为utf-8？

res.send(data)

res.send(data.toString(\"utf8\"));

var req = http.request(options, function(res) {
  console.log(\"statusCode: \", res.statusCode);
  console.log(\"headers: \", res.headers);
  **res.setEncoding(encoding=\'utf8\');** 
  res.on(\'data\', function(d) {
    console.log(d);
  });
});

res.setEncoding(\'utf8\');