写i！= 0会比i>快还是慢? 0为正整数? [英] Does writing i != 0 compare faster or slower than i > 0 for a positive integer?

问题描述

想象一下，我有一个程序需要检查变量i是否大于零. i始终为正，因此说i > 0等同于说i != 0.

Imagine I have a program that needs to check if a variable i is greater than zero. i is always positive, so saying that i > 0 is equivalent to saying i != 0.

这两个表达式之间是否存在性能差异?为什么?

Is there a performance difference between those two expressions and why?

我知道并没有明显的性能差异，这更多是一个哲学问题.

I am aware that there isn't a noticable performance difference, this is more of a philosophical question.

推荐答案

我认为这没有明显的不同，但是与流行的看法相反，我将告诉您使用!=而不是>或<是因为前者是一个更通用的操作，如果要将代码转换为C ++并使用 iterators 而不是指针，则并非所有迭代器都支持<或>(但它们全部都支持!=).

I don't think it's measurably different, but contrary to popular wisdom, I'm going to tell you to use != rather than > or < on the grounds that the former is a more general operation, and if you were going to convert your code to C++ and use iterators instead of pointers, not all iterators would support < or > (but all of them would support !=).

这篇关于写i！= 0会比i>快还是慢? 0为正整数?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！