modf()函数

函数名: modf 　　
功 能: 把数分为整数和小数 （The modf function breaks down the floating-point value x into fractional and integer parts, each of which has the same sign as x. The signed fractional portion of x is returned. The integer portion is stored as a floating-point value at intptr. 　　） 　　
用 法: double modf(double x, double *intptr); 　　
程序例: 　　
#include <math.h> 　　
#include <stdio.h> 　　
int main(void) 　　
{ 　　
   double fraction, integer; 　　
   double number = 100000.567; 　　
   fraction = modf(number, &integer); 　　
   printf("The whole and fractional parts of %lf are %lf and %lf\n",number, integer, fraction); 　　
    return 0; 　　
}
结果：
The whole and fractional parts of 100000.567 are 100000.000 and 0.567