The & operator deals with the binary format of a decimal number. So 10 & 9 = 8 because
1010 (10)
1001 (9)
=====
1000 (8)
This previous example runs fine. But when I try to do 010 & 010 I expect the result to be 10. However I get 8. Can anyone explain to me why this is happening ?
Because a number that starts with a 0 is considered as being octal, not binary.
10 is considered decimal, because it's default. So the 10 & 9 = 8 test is resolved in decimal.
When it starts with a 0, it's considered octal. So 010 & 010 is resolved in octal, as (in decimal): 8 & 8.
0x is considered as hexadecimal.
And as Oli Charlesworth and delnan pointed out to me, there's no C standard for binary, although some compilers (such as GCC) consider 0b as binary representation.
Interesting info here: Writing binary number system in C code
0b010 is, unfortunately, only available in C++11. Or is there an equivalent extension in GNU C or something? Edit: Actually, there is such an extension: stackoverflow.com/a/2612556/395760 -- whether it should be used is another question.
10is considered decimal, because it's default. When it starts with a0, it's considered octal.0xis considered as hexadecimal. As has been pointed out to me, there's no C standard for binary, although some compilers (such as GCC) consider0bas binary representation.