And so what I was hinting at earlier when you put semicolons in the wrong place, and then proceed to have curly braces around arbitrary lines of code, you're creating an even more local scope there, which is generally not the right intended behavior.

在之前我暗示了,当你把一个分号放在错误的地方时,然后开始用花括号,括上任意行的代码，你在那里创建了一个局部范围，那个不是故意的行为。

哈佛公开课 - 计算机科学课程节选

Well, for a thing called main which itself is a function but a function I wrote, a tool I am writing at the moment not like printf which someone else wrote long ago, I have to say where does main start, where does main end, and I do that by using these curly braces.

至于这个名曰main的函数,由我们自己写的函数，也是一个工具,只不过由我们自己编写，而不是像printf那样已经由前人写好了,我们必须要说明main在哪开始，在哪结束，这样我们就要用到大括号了。

哈佛公开课 - 计算机科学课程节选