You can say if this is true, then go and do the following pieces of code or puzzle pieces that are inside this part of the block, else go ahead and do these that are down here.

你可以说如果条件成立，执行下面的代码段,或板块中的拼图，否则跳过去执行这下面的语句。

哈佛公开课 - 计算机科学课程节选