#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

在Linux中是%llu,在Windows中是%I64u

虽然我发现它不能在Windows 2000中工作,但似乎有一个bug !

其他回答

您可能想尝试使用inttypes.h库,它可以为您提供诸如 Int32_t, int64_t, uint64_t等。 然后你可以使用它的宏,如:

#include <inttypes.h>

uint64_t x;
uint32_t y;

printf("x: %"PRIu64", y: %"PRIu32"\n", x, y);

这“保证”不会给您带来与long、unsigned long等相同的麻烦,因为您不必猜测每种数据类型中有多少位。

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。

%d——>为int

%u——>为unsigned int

%ld—>为长int或长

%lu——>用于unsigned long int或long unsigned int或unsigned long

%lld—>表示long long int或long long

%llu——>用于unsigned long long int或unsigned long long

在Linux中是%llu,在Windows中是%I64u

虽然我发现它不能在Windows 2000中工作,但似乎有一个bug !

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。