I copied the code, but the display is different. The data can be displayed
but it cannot be seen which level it is.
Post your code, how can we help you solve it? Post your code
Check yourself to see if there are any naming differences, capitalization, etc. . These may cause differences. . .
You can post part of the code so that no problem can be seen. I have tested the code in the tutorial and it works. Or you can make some modifications to the original code.
The data can be displayed
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Post your code, how can we help you solve it? Post your code
Check yourself to see if there are any naming differences, capitalization, etc. . These may cause differences. . .
You can post part of the code so that no problem can be seen. I have tested the code in the tutorial and it works. Or you can make some modifications to the original code.