变量在node.js http回调函数中增加两次 [英] Variable is incremented twice in node.js http callback function

问题描述

  var http = require（） http）; 
 var i = 0; 
 
 function onRequest（request，response）{
 response.writeHead（200，{Content-Type：text / plain}）; 
 response.write（You're number+ i ++）; 
 response.end（）; 
} 
 
 http.createServer（onRequest）.listen（8888）; 
  

我希望它的行为像一个页面浏览计数器，但每次刷新浏览器标签得到的结果似乎是 i = i + 2 而不是一个简单的增量。

解决方案

您的浏览器正在击中您的服务器 favicon.ico 。每个请求增加 i ，并请求 favicon.ico 计数。

使用 Fiddler 或 WireShark 自己看这个行为。

I was playing around with node.js and something strange happens when you run this code:

var http = require("http");
var i = 0;

function onRequest(request, response) {  
  response.writeHead(200, {"Content-Type": "text/plain"});
  response.write("You're number " + i++);
  response.end();
}

http.createServer(onRequest).listen(8888);

I would expect it to behave like a page views counter, but with each refresh of the browser tab i get the result of what seems to be i=i+2 instead of a simple increment. Could someone explain this behavior to me?

解决方案

Your browser is hitting your server for favicon.ico as well. Each request increments i, and the request for favicon.ico counts.

Use a tool such as Fiddler or WireShark to see this behavior yourself.

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