没有，一个不纯功能的是一款具有的副作用功能的

No, an "impure" function is a function with side-effects.

在换句话说，不管你有多少次调用它，的纯函数会影响什么比其输出其他的

In other words, no matter how many times you call it, a pure function will affect nothing other than its output.

例如， 富不纯 即使返回零的：

int x;
int foo() { x++; return 0; }
int bar() { return x; }

如果富是纯粹的，称它的不会的影响的结果吧（）。

If foo were pure, calling it would not affect the result of bar().

的printf 是不纯的，因为它的结果有副作用 - 具体而言，它打印屏幕上的内容（或文件等）结果。
如果是纯粹的，那么你可以把它叫做一个十亿倍，并确保没有什么不好会发生。结果
但是，如果你实际调用的printf 一万次，有一定的是的用户的不同 - 它填补了他的屏幕（或磁盘空间，管他呢）。所以很明显它不是纯粹的。

printf is impure because its result has "side effects" -- specifically, it prints something on the screen (or in a file, etc).
If it were pure, then you could call it a billion times and be sure nothing bad would happen.
But if you actually call printf a million times, there certainly is a difference to the user -- it fills up his screen (or disk space, or whatever). So clearly it's not pure.

另外：如果你的输出重定向到是自己的输入（有点没用，但仍），然后调用的printf 会影响您会收到来自的getchar 。 :)所以这是直接观察到的那样了。

Furthermore: If your output was redirected to be your own input (somewhat useless, but still), then calling printf would affect what you would receive from getchar. :) So it's directly observable that way, too.