如何显示从数组对象列表

我在node.js新。

我发一个返回对象的数组的函数。

当我尝试在控制台中显示，它会显示消息Undefined。

下面是函数：

async function allBucketKeys(s3, bucket) {
    const params = {
      Bucket: bucket,
    };

    var keys = [];
    for (;;) {
      var data = await s3.listObjects(params).promise();

      data.Contents.forEach((elem) => {
        keys = keys.concat(elem.Key);
      });

      if (!data.IsTruncated) {
        break;
      }
      params.Marker = data.NextMarker;
    }
    console.log(keys);

    return keys;
  } 

  var s3 = new AWS.S3()

 array = allBucketKeys(s3, "mymplifyroject-20190123180140-deployment").keys;

 console.log(array);

你回来从你的异步功能的承诺，所以你必须等待它或致电.then在它之前，你可以访问该值。

async function allBucketKeys(s3, bucket) {
  const params = {
    Bucket: bucket
  };

  var keys = [];
  for (;;) {
    var data = await s3.listObjects(params).promise();

    data.Contents.forEach(elem => {
      // You might want to use keys.push(elem.Key) here, but if elem.Key
      // is an array it would have a different behavior
      keys = keys.concat(elem.Key);
    });

    if (!data.IsTruncated) {
      break;
    }
    params.Marker = data.NextMarker;
  }
  console.log(keys);

  return keys;
}
var s3 = new AWS.S3();
allBucketKeys(s3, "mymplifyroject-20190123180140-deployment").then(keys => {
  console.log(keys);
});