1、如果说<span style="color:blue;">for</span>循环是针对<span style="color:blue;">变量</span>的循环 2、<span style="color:blue;">foreach</span>是针对<span style="color:blue;">数组</span>的循环 3、那么<span style="color:blue;">递归</span>就是针对<span style="color:blue;">函数代码块</span>的循环，或可以说是<span style="color:blue;">对象的循环调用</span>