#include <stdio.h>
int main() {
unsigned long long int num = 285212672; //FYI: fits in 29 bits
int normalInt = 5;
printf("My number is %d bytes wide and its value is %ul. A normal number is %d.\n", sizeof(num), num, normalInt);
return 0;
}
输出:
My number is 8 bytes wide and its value is 285212672l. A normal number is 0.
我假设这个意外的结果来自于输出unsigned long long int。你如何打印()一个unsigned long long int?
当前回答
Hex:
printf("64bit: %llp", 0xffffffffffffffff);
输出:
64bit: FFFFFFFFFFFFFFFF
其他回答
使用VS2005将其编译为x64:
%llu运行良好。
对于使用MSVS的long long(或__int64)，您应该使用%I64d:
__int64 a;
time_t b;
...
fprintf(outFile,"%I64d,%I64d\n",a,b); //I is capital i
如何使用printf格式化unsigned long long int ?
由于C99在转换说明符o,u,x, x之前使用了“ll”(ell-ell)。
很多答案中除了10进制选项外，还有16进制和8进制选项:
选择包括
unsigned long long num = 285212672;
printf("Base 10: %llu\n", num);
num += 0xFFF; // For more interesting hex/octal output.
printf("Base 16: %llX\n", num); // Use uppercase A-F
printf("Base 16: %llx\n", num); // Use lowercase a-f
printf("Base 8: %llo\n", num);
puts("or 0x,0X prefix");
printf("Base 16: %#llX %#llX\n", num, 0ull); // When non-zero, print leading 0X
printf("Base 16: %#llx %#llx\n", num, 0ull); // When non-zero, print leading 0x
printf("Base 16: 0x%llX\n", num); // My hex fave: lower case prefix, with A-F
输出
Base 10: 285212672
Base 16: 11000FFF
Base 16: 11000fff
Base 8: 2100007777
or 0x,0X prefix
Base 16: 0X11000FFF 0
Base 16: 0x11000fff 0
Base 16: 0x11000FFF
除了人们多年前写的:
你可能会在gcc/mingw上得到这个错误:
main.c:30:3:警告:未知转换类型字符'l'的格式[-Wformat=]
printf（“%llu\n”， k）;
那么你的mingw版本不会默认为c99。添加编译器标志:-std=c99。
一种方法是用VS2008将其编译为x64
这运行如你所料:
int normalInt = 5;
unsigned long long int num=285212672;
printf(
"My number is %d bytes wide and its value is %ul.
A normal number is %d \n",
sizeof(num),
num,
normalInt);
对于32位代码，我们需要使用正确的__int64格式说明符%I64u。所以它变成了。
int normalInt = 5;
unsigned __int64 num=285212672;
printf(
"My number is %d bytes wide and its value is %I64u.
A normal number is %d",
sizeof(num),
num, normalInt);
这段代码适用于32位和64位VS编译器。
