如何在ios4的xcode for iOS中将浮点数四舍五入为整数？

Question

可能重复：
Objective-c: How to round off Float values?

我知道它与NSNumberformatter类，任何示例代码吗？

Answer 1

由于int s不能存储浮点数，浮点数的小数部分将被截断，你将留下的整数：

float x = 3.14159; 
int y = (int)x; 

这工作，因为int只能够

：存储整数，因此它只是存储 x

---

见的整数部分也gnu C Library Rounding Functions的

— Function: double ceil (double x) 
— Function: float ceilf (float x) 
— Function: long double ceill (long double x) 
— Function: double floor (double x) 
— Function: float floorf (float x) 
— Function: long double floorl (long double x) 
— Function: double trunc (double x) 
— Function: float truncf (float x) 
— Function: long double truncl (long double x) 
— Function: double rint (double x) 
— Function: float rintf (float x) 
— Function: long double rintl (long double x) 
— Function: double nearbyint (double x) 
— Function: float nearbyintf (float x) 
— Function: long double nearbyintl (long double x) 
— Function: double round (double x) 
— Function: float roundf (float x) 
— Function: long double roundl (long double x) 
— Function: long int lrint (double x) 
— Function: long int lrintf (float x) 
— Function: long int lrintl (long double x) 
— Function: long long int llrint (double x) 
— Function: long long int llrintf (float x) 
— Function: long long int llrintl (long double x) 
— Function: long int lround (double x) 
— Function: long int lroundf (float x) 
— Function: long int lroundl (long double x) 
— Function: long long int llround (double x) 
— Function: long long int llroundf (float x) 
— Function: long long int llroundl (long double x) 
— Function: double modf (double value, double *integer-part) 
— Function: float modff (float value, float *integer-part) 
— Function: long double modfl (long double value, long double *integer-part) 

Answer 2

但是3.999也等于3，如果你只是将它转换为int。

float value = 3.14159f; 
int intValue = (int)value; 
float fractional = fmodf(value, (float)intValue); 
if(fractional > .5f) 
    intValue++; 

intValue是你的四舍五入整数。