C语言 如何将浮点数分成整数和小数部分？
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How to separate float into an integer and a fractional part?
提问by TheMatrix
I am willing to cast precise operations and for that purpose I need a way to seperate a float number into an integer and a fractional part. Is there any way for this?
我愿意进行精确的操作，为此我需要一种将浮点数分离为整数和小数部分的方法。有什么办法吗？
回答by Edenia
There is a function included in math.hlibrary called modfWith this function you can do just what are you trying to.
math.h库中包含一个名为modf 的函数。有了这个函数，您就可以做您想做的事。
Example:
例子：
#include <stdio.h>
#include <math.h>
double ftof ()
{
double floating = 3.40, fractional, integer;
fractional = modf(floating, &integer);
printf ("Floating: %g\nInteger: %g\nFractional: %g", floating, integer, fractional); // when using printf, there are no floats
return fractional;
}
Output:
输出：
Floating: 3.40
Integer: 3
Fractional: 0.40
Note that using doublein most of the cases is better than using float, despite that doubleconsumes twice the memory of float(4:8 bytes) hence the increased range and accuracy. Also in case you need more precise output from
bigger floating numbers when printing, you can try the printf()exponent format specifier %einstead of %gwhich only uses the
shortest representation of the floating decimal.
请注意，double在大多数情况下 using 比 using 更好float，尽管它double消耗了两倍的内存float（4:8 字节），因此增加了范围和准确性。此外，如果您在打印时需要从更大的浮点数中获得更精确的输出，您可以尝试使用printf()指数格式说明符，%e而不是%g仅使用浮点小数的最短表示。
回答by Vishwanath Hiremath 16210107
One other way using type cast.
使用类型转换的另一种方式。
#include <stdio.h>
#include <math.h>
void main()
{
float a = 3.4;
float a_frac = a - (int) a;
float a_int = a - a_frac;
printf("Number = %f, Integer = %f, Fraction = %f", a, a_frac, a_int);
}
回答by Ankit Jaiswal
A thought crossed my mind to separate them with some logic :
一个想法掠过我的脑海，用一些逻辑将它们分开：
#include <iostream>
using namespace std;
int main()
{
double fr,i,in,num=12.7;
for(i=0;i<num;i++)
{
fr=num-i;
}
cout<<"num: "<<num;
cout<<"\nfraction: "<<fr;
in=num-fr;
cout<<"\nInteger: "<<in;
}
Hope this was what you were searching for:) .
希望这是您正在寻找的内容:)。
