如何在nodejs中发送返回错误码

const http = require('http');
const url = require('url');

const server = http.createServer((req, res) => {
  // 解析请求路径
  const parsedUrl = url.parse(req.url, true);

  // 根据路径处理不同的请求
  if (parsedUrl.pathname === '/api') {
    // 处理API请求的逻辑

    // 如果发生错误，发送错误码
    const errorCode = 500;
    res.statusCode = errorCode;
    res.end(`An error occurred with status code ${errorCode}`);
  } else {
    // 处理其他请求的逻辑

    // 如果路径不存在，发送404错误码
    const errorCode = 404;
    res.statusCode = errorCode;
    res.end(`Not found with status code ${errorCode}`);
  }
});

const port = 3000;
server.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});