Two Equal Signs in One Line?

Question

Could someone please explain what this does and how it is legal C code? I found this line in this code: http://code.google.com/p/compression-code/downloads/list, which is a

Answer 1

ArcChar = ArcBit = 0;

The assignment is left-associative, so it's equivalent to:

ArcChar = (ArcBit = 0);

The result of ArcBit = 0 is the newly-assined value, that is - 0, so it makes sense to assign that 0 to ArcChar