This thing's nice because rather than do "if" and "and and" or "or or" and all of this, you can instead enumerate things a little more cleanly, albeit apparently at the expense of more white space.

这个东西是不错的，因为它不用“if“和“and，and“,或者“or，or“所有的这些，你可以用枚举来更清楚地表达它，虽然表面上它用了更多的空格。

哈佛公开课 - 计算机科学课程节选