Preincrement比postincrement在C ++ - 真的吗？如果是，为什么呢？ [英] Preincrement faster than postincrement in C++ - true? If yes, why is it?

问题描述

可能重复：

我听说这个preincrements（++ i）比C ++中的postincrements（i ++）有点快。真的吗？这是什么原因呢？

I heard about that preincrements (++i) are a bit faster than postincrements (i++) in C++. Is that true? And what is the reason for this?

推荐答案

后增量通常涉及保持上一个值的副本，额外代码。预增量只是做它的工作，并得到的方式。我通常预先增加，除非语义将改变，后增量实际上是必要的。

Post-increment usually involves keeping a copy of the previous value around and adds a little extra code. Pre-increment simply does it's job and gets out of the way. I typically pre-increment unless the semantics would change and post-increment is actually necessary.

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