PHP Class not found

Question

第一次使用PHP，从github上拉下来一个项目(项目地址)，我新建了一个index.php，然后写下图中代码，为什么一直报错呢？
路径觉得没问题啊？

Answer 1

You wrote it yourselfindex.php，需要引入vender的autoload.php.
If you use a framework, the framework itself has already implemented the class automatic loading and registration mechanism.

Answer 2

https://getcomposer.org/
http://www.phpcomposer.com/

Look at the composer's documentation. vendor is the composer's library directory. If you want to use it directly, you can use a relative directory reference.
General use should be to introduce the autoload.php file in the vendor directory outside the vendor directory

Answer 3

The autoloading function is not registered and the class is not loaded

Answer 4

Quick fix by referencing the namespace at the top of the page