1、如果說<span style="color:blue;">for</span>循環是針對<span style="color:blue;">變量</span>的循環 2、<span style="color:blue;">foreach</span>是針對<span style="color:blue;">數組</span>的循環 3、那么<span style="color:blue;">遞歸</span>就是針對<span style="color:blue;">函數代碼塊</span>的循環，或可以說是<span style="color:blue;">對象的循環調用</span>