PHP：检查目录是否为空的最佳和最简单的方法是什么

I got a root directory with 100s of dynamically generated folders. As time goes some of these folders will need to be extirpated from system on the condition that this(ese) directories(s) must be empty. What would be the best shortest, easiest and/or most effective way to achieve that?I got a root directory with 100s of dynamically