为什么我看到一个双变量初始化为 21.4 之类的某个值作为 21.399999618530273? [英] Why do I see a double variable initialized to some value like 21.4 as 21.399999618530273?

问题描述

double r = 11.631;
double theta = 21.4;

在调试器中，这些显示为 11.631000000000000 和 21.399999618530273.

In the debugger, these are shown as 11.631000000000000 and 21.399999618530273.

我怎样才能避免这种情况?

How can I avoid this?

推荐答案

这些准确性问题 是由于浮点数的内部表示，您无能为力避免它.

These accuracy problems are due to the internal representation of floating point numbers and there's not much you can do to avoid it.

顺便说一句，在运行时打印这些值通常仍然会产生正确的结果，至少使用现代 C++ 编译器是这样.对于大多数操作来说，这不是什么大问题.

By the way, printing these values at run-time often still leads to the correct results, at least using modern C++ compilers. For most operations, this isn't much of an issue.

这篇关于为什么我看到一个双变量初始化为 21.4 之类的某个值作为 21.399999618530273?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！