node.js - node 回调函数中 var temp = this 的意义

Question

在feedparser的示例中，我看到如下代码： {代码...} 令人疑惑的是，在此处的回调函数中，示例代码使用var stream = this。 是为了使得代码逻辑更加清晰吗？ 还是有什么特殊的作用？

天蓬老师 · Answer

See notes:

this is req, which is a streamthis is req, which is a stream

此时this指向req，而req对外可以当做是stream

At this time, this points to req, and req can be used as stream externally, just changing the name , it seems clearer, it has no special meaning. 🎜

迷茫 · Answer

I can only say that this demo is poorly written, and there is no need to be superstitious and overly speculate on its intentions.

Normal similar writing is like this

var xx = function() {
    var that = this;
    
    return funtion() {
        that.xxx
    }
}

You can reference this in the upper scope in the closure