c输出格式

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <math.h>
 4 
 5 int main()
 6 {
 7     //取整
 8     printf("%ld
",(long)19.999);
 9     //保留0位小数部分
10     printf("%.lf
",19.999);
11 
12     //四舍五入
13     //(long)是取整最右边的数据，而数据与数据之间以运算符号分开
14     //所以一定要把数据和0.5用括号括起来，否则输出为0
15     printf("%ld
",(long)(19.5+0.5));
16     printf("%ld
",(long)(19.49+0.5));
17     printf("%ld
",(long)(19.51+0.5));
18 
19     //整型用abs，实型用fabs
20     printf("%ld
",abs(-5));
21     printf("%lf
",fabs(-5.123));
22     return 0;
23 }