為什么對象值被壓入數組3次？

Question

我有一個簡單的對象數組，其中將2個字段推入一個對象：bucketName和Date。 問題是這些值被三次推送到數組中。 請幫我。

JS：

sortBucket: function(bucketList) {
    var counter, j = 0;
    var str = "aws-billing-csv";
    console.log("Bucket List :: ", bucketList);

    bucketList.forEach(function(bucket, index) {
        (function(bucketId) {
            var bucketObj = {};
            // console.log("Bucket Id :: ",bucketId);
            s3Client.listObjects(params = {Bucket: bucketId }, function(err, data) {
                var csvBucketArr = [];
                if (err) {
                    document.getElementById('status').innerHTML = 'Could not load objects from ' + bucketID;
                }
                else{        
                    //console.log("Bucket Data "+index+" :: ",data);
                    data.Contents.forEach(function(content,contentIndex){
                        var fileKey = content.Key;
                        if(fileKey.search(str) != -1) {
                            // console.log("fileKey["+bucketId+"] "+contentIndex+" :: ",fileKey + "  Date :: " ,content.LastModified);
                            bucketObj[fileKey] = {
                                lastModified    : content.LastModified,
                                bucketName      : bucketId
                            }
                            if(!jQuery.isEmptyObject(bucketObj)){
                                csvBucketArr.push(bucketObj);
                            }
                        }
                    });
                    csv = csvBucketArr;
                  }
                  if(csvBucketArr.length!==0)
                      console.log("csvBucketArr :: ",csvBucketArr));
                  });
             }(bucket.bucketName));
            // console.log("Bucket " + index + " :: ", bucket);
          });
       },

Answer 1

您將在以下每次迭代中將同一對象推入數組：

data.Contents.forEach(function(content,contentIndex){...});

因此， .forEach()循環的多次迭代，您最終將完全相同的bucketObj對象推入csvBucketArr數組。

如果您希望該.forEach()每次迭代將一個新的和不同的bucketObj對象放入數組中，則每次在該循環內都需要創建一個新對象，如下所示：

sortBucket: function(bucketList) {
    var counter, j = 0;
    var str = "aws-billing-csv";
    console.log("Bucket List :: ", bucketList);

    bucketList.forEach(function(bucket, index) {
        (function(bucketId) {
            // console.log("Bucket Id :: ",bucketId);
            s3Client.listObjects(params = {Bucket: bucketId }, function(err, data) {
                var csvBucketArr = [];
                if (err) {
                    document.getElementById('status').innerHTML = 'Could not load objects from ' + bucketID;
                }
                else{        
                    //console.log("Bucket Data "+index+" :: ",data);
                    data.Contents.forEach(function(content,contentIndex){
                        // ===> create new bucketObj object
                        var bucketObj = {};
                        var fileKey = content.Key;
                        if(fileKey.search(str) != -1) {
                            // console.log("fileKey["+bucketId+"] "+contentIndex+" :: ",fileKey + "  Date :: " ,content.LastModified);
                            bucketObj[fileKey] = {
                                lastModified    : content.LastModified,
                                bucketName      : bucketId
                            }
                            if(!jQuery.isEmptyObject(bucketObj)){
                                csvBucketArr.push(bucketObj);
                            }
                        }
                    });
                    csv = csvBucketArr;
                  }
                  if(csvBucketArr.length!==0)
                      console.log("csvBucketArr :: ",csvBucketArr));
                  });
             }(bucket.bucketName));
            // console.log("Bucket " + index + " :: ", bucket);
          });
       },