检查双变量是否包含整数，而不是浮点

2022-01-09 00:00:00 floating-point c c++

我的意思是:

  double d1 =555;
  double d2=55.343

我想知道 d1 是一个整数，而 d2 不是.有没有简单的方法在 c/c++ 中做到这一点?

I want to be able to tell that d1 is an integer while d2 is not. Is there an easy way to do it in c/c++?

推荐答案

使用<代码>std::modf:

double intpart; modf(value, &intpart) == 0.0

不要转换成 int！1.0e+300 这个数字也是你知道的整数.

Don't convert to int! The number 1.0e+300 is an integer too you know.

正如 Pete Kirkham 指出的那样，标准不能保证将 0 作为第二个参数传递，这需要使用虚拟变量，不幸的是，这使得代码不那么优雅.

As Pete Kirkham points out, passing 0 as the second argument is not guaranteed by the standard to work, requiring the use of a dummy variable and, unfortunately, making the code a lot less elegant.

相关文章