小编Rut*_*rns的帖子

我有点问题。这是代码：

情况一：

var foundRiders = [];

            riders.forEach(function(rider){
                Rider.findOne({_id: rider}, function(err, foundRider){
                    if(err){
                        console.log("program tried to look up rider for the forEach loop finalizing the results, but could not find");
                    } else {
                        foundRiders.push(foundRider);
                        console.log(foundRiders);
                    }
                });
            });

情况B

var foundRiders = [];

            riders.forEach(function(rider){
                Rider.findOne({_id: rider}, function(err, foundRider){ 
                    if(err){
                        console.log("program tried to look up rider for the forEach loop finalizing the results, but could not find");
                    } else {
                        foundRiders.push(foundRider);
                    }
                });
            });
            console.log(foundRiders);

因此，在情况 A 中，当我控制台日志时，我发现 foundRiders 是一个充满对象的数组。在情况 B 中，当我将 …