node.js 显示“未定义"；在控制台上

问题描述

最近我在我的 Windows 7 机器上安装了 node.js.

Recently I installed node.js on my Windows 7 machine.

在执行 JavaScript 时，我收到一条 undefined 消息以及表达式的成功执行.

On execution of JavaScript, I get an undefined message along with successful execution of the expression.

这里有什么问题?我没有注意到任何其他副作用.

What's wrong here? I have not noticed any other side effects.

推荐答案

只要写 "hello world"; 然后回车...它会返回 "hello world" 而不是 undefined，因此不会显示 undefined.console.log 返回 undefined 并将参数记录到控制台，以便您获得多条消息.

Just write "hello world"; and hit enter... it will return "hello world" instead of undefined, thus no undefined is displayed. console.log returns undefined and also logs arguments to console so you get multiple messages.