Objective-C - 获取双变量的小数位数 [英] Objective-C - Get number of decimals of a double variable

问题描述

有没有一个很好的方法来获取Objective-C中的double变量的小数位数？
我正在努力寻找一种方式，但没有成功。

例如，231.44232000应该返回5。

提前感谢

解决方案

你可以在循环中乘以10直到小数部分由modf（）返回）真的接近零。迭代次数将是您之后的答案。如下：

  int countDigits（double num）{
 int rv = 0; 
 const double insignificantDigit = 8; 
 double intpart，fracpart; 
 fracpart = modf（num，& intpart）; $（
）（（fabs（fracpart）> 0.000000001f）&（rv< insignificantDigit））{
 num * = 10; 
 rv ++; 
 fracpart = modf（num，& intpart）; 
} 
 
 return rv; 
} 
  

Is there a nice way to get the number of decimals of a double variable in Objective-C? I am struggling for a while to find a way but with no success.

For example 231.44232000 should return 5.

Thanks in advance.

解决方案

You could, in a loop, multiply by 10 until the fractional part (returned by modf()) is really close to zero. The number of iterations'll be the answer you're after. Something like:

int countDigits(double num) {
  int rv = 0;
  const double insignificantDigit = 8;
  double intpart, fracpart;
  fracpart = modf(num, &intpart);
  while ((fabs(fracpart) > 0.000000001f) && (rv < insignificantDigit)) {
    num *= 10;
    rv++;
    fracpart = modf(num, &intpart);
  }

  return rv;
}

这篇关于Objective-C - 获取双变量的小数位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！