How to convert hexadecimal to binary

Question

What's the representation of 0x2b in binary? And how to convert it ? Im a little confused about b .

char a = 0x2b;

Answer 1

The 0x part means the following number is in hexadecimal notation.

Since in hex, 0x10 == 16 and 0xb = 11 , we have:

0x2B = 0x20 + 0xB = 32 + 11 = 43

So 0x2B is 43 in decimal (the system we commonly use), and that's

101011

in binary.

To clarify, no matter what notation you use (decimal or hexadecimal) to declare/overwrite variables in C, the result is the same.

char a = 0x2B;
char b = 43;
if (a == b)
    printf("But of course they're the same!\n");
else
    printf("This should not happen\n");