module.exports 未在 Node.js 中返回结果

Question

I have this function in a latestVideo.js file:

function getLatestVideo() {
  request(url, function (error, response, body) {
    if (!error && response.statusCode === 200) {
      let reqBody = body.toString();
      reqBody = JSON.parse(reqBody);

      const latestVideoID = reqBody.items['0'].id.videoId;
      return videoLink + latestVideoID;
    }
  });

}
module.exports.getLatestVideo = getLatestVideo;

Then in another file I want to use the output of the function like:

const latestVideo = require('./latestVideo');

console.log(latestVideo.getLatestVideo)

But it does not execute the function. It just says [Function: getLatestVideo] in my console. But I return a value right, so why is the function not executing?

Answer 1

Try it like this: latestVideo.getLatestVideo()

You get undefined because you doesnt return anything. You use return in an callback function. Here is a solution for your problem:

async function getLatestVideo() {
   return await new Promise((resolve) => {
      request(url, function (error, response, body) {
         if (!error && response.statusCode === 200) {
            let reqBody = body.toString();
            reqBody = JSON.parse(reqBody);
            const latestVideoID = reqBody.items['0'].id.videoId;
            resolve(videoLink + latestVideoID);
         }
     });
   })
}

Answer 2

You're not running the function just returning the function

make latestVideo.getLatestVideo to latestVideo.getLatestVideo()