The format is the same. I'm going to ask for some input, and then I am going to use that procedure to check, is this the right type of value. And I'm trying to use that to do the coercion if you like. Same thing if it works, I'm going to skip that, if it not, it's going to throw the exception.

格式是一样的，我需要一些输入,然后我要用一个过程来检查,是否是正确的值,然后你就可以做强制转换了,如果能运行，那是一样的，我打算跳过这段，如果不正确，那就会抛出一个异常。

麻省理工公开课 - 计算机科学及编程导论课程节选

So what's going to happen here? If I'm inside this FOR, OK, and I'm running around, if I ever hit a place where this test is true, I'm going to execute that return, return that return returns from the entire procedure. OK? So the return comes back from the procedure.

那么这里发生了什么呢？,如果我是在这个for循环里面，我正在运行，如果我运行到test的值为真的地方，我就会执行,这个return将会返回整个程序的值,明白了吗？所以它将会从整个程序中返回值。

麻省理工公开课 - 计算机科学及编程导论课程节选