#include<stdio.h>
void main()
{
    float x;
    printf("input x:\n");
    scanf("%f",&x);
    printf[un]("%.0f[/un]\n",x);
}                        
                                                                                                                                                                                                                                                                                                                                                                                                                                           那个"%.0f"是什么意思                                                                                                                                                                                                                                                                                                                                                                                                                                         

"%.0f"是指不输出小数位

谢谢沼泽的指点.
但是这个程序是一个近似整数的输出程序,如15.3和15.6分别输出的是15,16

这是因为当不输出小数位的时候，编译器会对float型的小数位进行4舍5入的操作

原来如此!!!
THANKS !!