How is the hexadecimal numbers translated?

Question

why this behavior?
https://code.sololearn.com/cMA8qPbY7SmI/?ref=app

Answer 1

Try with this:
printf("Varible a is equal to 0xE0? %d", a == (char)0xE0);

You can also declare a as an unsigned char instead.

The thing is, this 0xE0 is considered to be an int, so the variable a is cast to an int for the comparison, and since its value is negative (leftmost bit at 1), it becomes 0xffffffE0 when sign-extended.

https://code.sololearn.com/cZgn97tb2b11/?ref=app

Answer 2

0x just means it is using hexadecimal notation.

Answer 3

EDIT: Maybe you know this already...

Hexadecimal is essentially a number system with 6 new characters: a, b, c, d, e and f. It is case-insensitive.

So, instead starting the second digit once you get past 9, you keep going until you get past f.

This means hexademical is a base 16 number system. The normal decimal system is base 10. Binary is base 2.

This is me counting from 0 to 20 in hexadecimals... 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, 10, 11, 12, 13, 14.

In hexadecimals the highest two digit number is ff, which is 255 in regular decimals. This allows a RBG colour to be stored in six digits.

Answer 4

but doesn't occur any extansion/casting in my code.

or happens?

The 0xE0 is trated as int by the compiler???

Answer 5

really... I was thinking that the expression in 0x was a byte size. Wrong suposition.

Thank to to show me that

Answer 6

In my mind,the things would work as

0xFF (char)
0xFFFFFFFF (int)
0xFFFFFFFFFFFFFFFF (long)

and go on... lololol