向后打印无符号字符的二进制表示形式？

Question

How exactly does this code work? I'm confused about the first for loop since binary starts at 0 and as long as it is not equal to the binary representation of the char it will increase, so then binary is 1 and so on?

unsigned char c; int binary;

scanf("%c", &c);
getchar();

printf("The decimal representation is: %d\n", c);

for (binary = 0; (1<<binary)<=c; binary++){  // moving to the left
}                                           // until binary code matches c

printf("The backwards binary representation is: ");

for (int i=0; i<binary; i++){   // since we know the size
    printf("%d", ((c>>i)&1));   // 1s and 0s are shifted to right
}

printf("\n");
return 0;

Answer 1

This:

for (binary = 0; (1<<binary)<=c; binary++)

simply counts how many significant bits are in the integer "c".

For instance, if "c" is 0101100 in binary, the most significant bit is the 6th from the right, and "binary" would be set to 6.

If "c" is 01 in binary, the most significant bit is the first from the right, and "binary" would be set to 1.

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The biggest problem with this code is its almost useless comments. If there must be comments, replace this:

/* moving to the left until binary code matches c */

with this:

/* Count number of significant bits.*/

Comments should say why the code is there, not describe how it works.

Comments like this don't serve any purpose:

/* since we know the size 1s and 0s are shift to right */

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The second biggest problem is the variable names. "binary" is misleading. Call it "number_of_significant_bits" instead and the code almost doesn't need any comments.