二进制打印用C不工作(Binary print not working in C)

我想打印C 32位二进制使用位掩码但二进制表示未在if语句得到打印。

unsigned int bit_mask = 2147483648;
int decimal = 2;
printf("\nBinary representation of 2: \n");
while(bit_mask > 0){
    if((decimal & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

decimal = 255;
printf("\n\nBinary representation of 255: \n");
while(bit_mask > 0){
    if((decimal & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

decimal = 32;
printf("\n\nBinary representation of 32: \n");
while(bit_mask > 0){
    if((decimal & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

decimal = -1;
printf("\n\nBinary representation of -1: \n");
while(bit_mask > 0){
    if((decimal & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

decimal = -255;
printf("\n\nBinary representation of -255: \n");
while(bit_mask > 0){
    if((decimal & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

int random_number =  (rand() % INT_MAX) + (rand() % INT_MIN);
printf("\n\nBinary representation of %d: \n", random_number);
while(bit_mask > 0){
    if((random_number & bit_mask) == 0)
        printf("0");
    else
        printf("1");
    bit_mask = bit_mask >> 1;
}

PS：程序现在只工作2 ，但仍然不打印其它值（255，32，-1，-255）

如果BLUEPIXY和我建议的修正是由，代码将产生正确的顺序位的答案。

#include <stdio.h>

int main(void)
{
    for (unsigned value = 2; value < 1024; value = value * 3 + 1)
    {
        unsigned bit_mask = 0x80000000;  // 2147483648

        printf("Binary representation of %3u: ", value);
        while (bit_mask > 0)
        {
            if ((value & bit_mask) == 0)
                printf("0");
            else
                printf("1");
            bit_mask >>= 1;
        }
        putchar('\n');
    }
    return 0;
}

输出：

Binary representation of   2: 00000000000000000000000000000010
Binary representation of   7: 00000000000000000000000000000111
Binary representation of  22: 00000000000000000000000000010110
Binary representation of  67: 00000000000000000000000001000011
Binary representation of 202: 00000000000000000000000011001010
Binary representation of 607: 00000000000000000000001001011111

输出不反转，尽管什么BLUEPIXY说在注释。

所述循环体可以被转换成一个功能，诸如void print_binary(unsigned value)以最小的努力，并且然后将被从一个循环调用。或多或少同一回路的编辑问题写出来六次是很滑稽（！） - 不写这样的代码。当你copy'n'paste这样的代码，有要写入的功能等待。

#include <stdio.h>

void print_binary(unsigned value)
{
    unsigned bit_mask = 0x80000000;  // 2147483648

    while (bit_mask > 0)
    {
        if ((value & bit_mask) == 0)
            printf("0");
        else
            printf("1");
        bit_mask >>= 1;
    }
}

此功能可用于打印的二进制表示unsigned int而不添加任何装饰。它可以合理地普遍使用。在这个特定背景，你可以写一个包装函数来处理其他格式：

void fmt_binary(int value)
{
    printf("Binary representation of %3d: ", value);
    print_binary((unsigned)value);
    putchar('\n');
}

因为你有一个原型演员是没有必要的，只要print_binary()的范围。从C99开始，你必须有一个当前功能的声明，但是，这并不一定是一个原型。然而，编译没有原型现在是愚蠢的。而且你会发现，确保如果你试图吝啬你的编译器抱怨的选项。对于GCC，您可以使用：

gcc -std=c11 -O3 -g -Wall -Wextra -Werror -Wmissing-prototypes -Wstrict-prototypes …

您可能会或可能不会增加-Wold-style-declaration或-Wold-style-definition取决于你正在处理的代码库和GCC的版本，您正在使用（和你是在写代码怎么不小心）。还有你会考虑其他的选择，比如-Wshadow ，但如果你的代码清单所示完全编译，这是不可能碰到不属于逻辑问题的许多问题。

随着fmt_binary()定义的，你可以写main()

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

// … declarations or definitions of fmt_binary and print_binary

int main(void)
{
    for (int value = 2; value < 1024; value = value * 3 + 1)
        fmt_binary(value);
    fmt_binary(2);
    fmt_binary(255);
    fmt_binary(32);
    fmt_binary(-1);
    fmt_binary(-255);
    srand(time(0));     // Better than no call to srand()
    int random_number =  (rand() % INT_MAX) + (rand() % INT_MIN);
    fmt_binary(random_number);
    return 0;
}

示例输出可能是：

Binary representation of   2: 00000000000000000000000000000010
Binary representation of   7: 00000000000000000000000000000111
Binary representation of  22: 00000000000000000000000000010110
Binary representation of  67: 00000000000000000000000001000011
Binary representation of 202: 00000000000000000000000011001010
Binary representation of 607: 00000000000000000000001001011111
Binary representation of   2: 00000000000000000000000000000010
Binary representation of 255: 00000000000000000000000011111111
Binary representation of  32: 00000000000000000000000000100000
Binary representation of  -1: 11111111111111111111111111111111
Binary representation of -255: 11111111111111111111111100000001
Binary representation of -1758826555: 10010111001010100110111111000101