如何使用printf格式化unsigned long long int？

Question

#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.

我认为这个意想不到的结果是来自打印unsigned long long int.你怎么printf()了unsigned long long int？

Answer 1

将ll(el-el)long-long修饰符与u(无符号)转换一起使用.(适用于Windows,GNU).

printf("%llu", 285212672);

Answer 2

您可能需要使用inttypes.h库,让你的类型,如尝试 int32_t,int64_t,uint64_t等等,那么你可以使用它的宏,例如:

uint64_t x;
uint32_t y;

printf("x: %"PRId64", y: %"PRId32"\n", x, y);

这是"保证"不给你同样的麻烦的long,unsigned long long等等,因为你不必去猜测有多少位是每个数据类型.

Answer 3

%d- >为 int

%u- >为 unsigned int

%ld- >为 long int

%lu- >为 unsigned long int

%lld- >为 long long int

%llu- >为 unsigned long long int

Answer 4

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

Answer 5

这是因为%llu在Windows下无法正常工作,%d无法处理64位整数.我建议改用PRIu64,你会发现它也可以移植到Linux上.

试试这个:

#include <stdio.h>
#include <inttypes.h>

int main() {
    unsigned long long int num = 285212672; //FYI: fits in 29 bits
    int normalInt = 5;
    /* NOTE: PRIu64 is a preprocessor macro and thus should go outside the quoted string. */
    printf("My number is %d bytes wide and its value is %" PRIu64 ". A normal number is %d.\n", sizeof(num), num, normalInt);
    return 0;
}

产量

My number is 8 bytes wide and its value is 285212672. A normal number is 5.

Answer 6

在Linux中,它就是%llu在Windows中%I64u

虽然我发现它在Windows 2000中不起作用,但似乎有一个错误!

Answer 7

使用VS2005将其编译为x64:

%llu效果很好.

Answer 8

如何格式化unsigned long long intusing printf？

"ll"由于 C99在转换说明符之前使用(ell-ell) o,u,x,X。

许多答案中除了以 10 为基数的选项外，还有以 16 为基数和以 8 为基数的选项：

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