Microsoft Windows [版本 6.1.7601]
版权所有 (c) 2009 Microsoft Corporation。保留所有权利。

C:\Windows\system32>node
> alert
ReferenceError: alert is not defined
    at repl:1:1
    at REPLServer.defaultEval (repl.js:132:27)
    at bound (domain.js:254:14)
    at REPLServer.runBound [as eval] (domain.js:267:12)
    at REPLServer.<anonymous> (repl.js:279:12)
    at REPLServer.emit (events.js:107:17)
    at REPLServer.Interface._onLine (readline.js:214:10)
    at REPLServer.Interface._line (readline.js:553:8)
    at REPLServer.Interface._ttyWrite (readline.js:830:14)
    at ReadStream.onkeypress (readline.js:109:10)
> document
ReferenceError: document is not defined
    at repl:1:1
    at REPLServer.defaultEval (repl.js:132:27)
    at bound (domain.js:254:14)
    at REPLServer.runBound [as eval] (domain.js:267:12)
    at REPLServer.<anonymous> (repl.js:279:12)
    at REPLServer.emit (events.js:107:17)
    at REPLServer.Interface._onLine (readline.js:214:10)
    at REPLServer.Interface._line (readline.js:553:8)
    at REPLServer.Interface._ttyWrite (readline.js:830:14)
    at ReadStream.onkeypress (readline.js:109:10)
>

> var i = 0; while (i <= 5)
...  {
... console.log("数字是 " + i)
... console.log("<br />")
...  i++
...  }
数字是 0
<br />
数字是 1
<br />
数字是 2
<br />
数字是 3
<br />
数字是 4
<br />
数字是 5
<br />
5

可以看得出v8引擎 alert和document是没有定义的，这不难理解，没有view就没有必要操作document了，不知道控制台（C# java）程序能否弹出一个对话框。

将前端代码移植到nodejs 需要重构代码，不能有dom操作。