All right, you can see that this little piece of code, it's got a loop in there, and what's it doing?

好，你们看到的这一小块代码,是做了一个循环吧？,他在做什么？

麻省理工公开课 - 计算机科学及编程导论课程节选

Well I ought to be able to do that by simply generalizing the loop. And that's what the next piece of code on your a hand out shows you.

好的通过生成这个循环,我应该能够达到目的,这也是你们的讲义中下一段代码。

麻省理工公开课 - 计算机科学及编程导论课程节选

Then we have to steal the code from earlier to do a forever loop, a while true loop and then I'm gonna go ahead and use that printf thing that we saw.

然后再借用先前的代码,做一个永久性的循环，即while循环,紧接着需要用到一个,之前我们看到过的printf函数。

哈佛公开课 - 计算机科学课程节选

Now I have the ability to create a loop, that is, to reuse the same pieces of code over and over again as I go around.

现在我们已经学会如何创建循环了，也就是，重复的一遍又一遍的,执行同一片代码。

麻省理工公开课 - 计算机科学及编程导论课程节选

Meaning, I'm just going to write a little loop that does that. All right, so let's go back to our code. That's right, let me pull this over a little bit, so I can see it. And what I'd like you to look at, I'm going to highlight it just for a second here, is those two pieces of code.

意思就是我只需,写一个小循环就可以了,让我们回到代码,让我们向下拉一点,我才看得见,我希望你看看这里。

麻省理工公开课 - 计算机科学及编程导论课程节选

At the end of the day, you can implement the exact same program using a while loop that you can using a for loop, it's just your code is going to look slightly different.

最终，你可以执行这个程序,再使用for循环的地方使用while循环，这只是使你的代码看起来稍微有点不同。

哈佛公开课 - 计算机科学课程节选

So conceptually the key difference here, besides the syntax looking slightly different, it just means that if you want a chunk of code to execute no matter what initially, ; you can use the do while loop; if you want to check a condition first, you can use the while loop.

所以概念上，则关键的区别是，除了语法看起来有点不同，它的意思是如果你想要一段代码,最初无论如何都要执行，你就可以用do，while循环;,如果你想要先检查条件，你可以用while循环。

哈佛公开课 - 计算机科学课程节选

I'm again, iterating with this four loop, same code as before.

我再次，重复使用for循环，同样的代码。

哈佛公开课 - 计算机科学课程节选

So in other words, if you terminate these lines early, if you terminate the four loop early, if you terminate an if condition early with that semicolon, the code may very well work; and this is a common source -- of frustration and conundrum because you don't -- because your code looks right and yet it's misbehaving, but that semicolon means stop looking for subsequent lines of related code.

换句话说，如果你用分号过早的终止了这些代码行，如果你过早地终止了那个for循环，如果如此,一个if条件，代码可能可以运行，这就是,挫折和问题产生的源头，因为你没有-,因为你的代码看起来是正确的，但是运行是错误的，那个分号的意思是,停止寻找后面相关的代码。

哈佛公开课 - 计算机科学课程节选

And you'll find in the end that recursion is a feature of a language, it allows you to map some very obvious concepts like the phonebook tearing in half and half and half and half to actual code without it using some arbitrary human contrived framework like a for loop or a while loop which are much more stilted mechanisms.

最后你会发现递归是某种语言的一种特征,你可以用它将一些非常明显的思想,比如将电话簿划分为一半又一半,映射为实际代码，而不必使用那些人为框架,像for循环，while循环之类的,那是很呆板的机制。

哈佛公开课 - 计算机科学课程节选