readable.setEncoding(encoding)

• encoding <string> 要使用的编码。
• 返回：<this>

readable.setEncoding() 方法用于设置从 Readable 流读取的数据的字符编码。

【The readable.setEncoding() method sets the character encoding for data read from the Readable stream.】

默认情况下，不会指定任何编码，流数据将以 Buffer 对象的形式返回。设置编码会导致流数据以指定编码的字符串形式返回，而不是 Buffer 对象。例如，调用 readable.setEncoding('utf8') 会使输出数据被解释为 UTF-8 数据，并作为字符串传递。调用 readable.setEncoding('hex') 会使数据以十六进制字符串格式编码。

【By default, no encoding is assigned and stream data will be returned as Buffer objects. Setting an encoding causes the stream data to be returned as strings of the specified encoding rather than as Buffer objects. For instance, calling readable.setEncoding('utf8') will cause the output data to be interpreted as UTF-8 data, and passed as strings. Calling readable.setEncoding('hex') will cause the data to be encoded in hexadecimal string format.】

Readable 流将正确处理通过流传递的多字节字符，如果仅作为 Buffer 对象从流中获取，这些字符可能会被错误解码。

【The Readable stream will properly handle multi-byte characters delivered through the stream that would otherwise become improperly decoded if simply pulled from the stream as Buffer objects.】

const readable = getReadableStreamSomehow();
readable.setEncoding('utf8');
readable.on('data', (chunk) => {
  assert.equal(typeof chunk, 'string');
  console.log('Got %d characters of string data:', chunk.length);
}); 拷贝