在node文档查不到介绍，运行node后NODE_ENV是undefined，看别人说默认值是development
求解，这个环境变量是哪里来的
欢迎选择我的课程，让我们一起见证您的进步~~
In the terminal, you use the terminal to enter your project directory, and then set export NODE_ENV=test, and then you can get the test value in the code.
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
In the terminal, you use the terminal to enter your project directory, and then set export NODE_ENV=test, and then you can get the test value in the code.