Question

I have the following code that I’m reading through:

if( (i%2) == 0 ){ 
    *d = ((b & 0x0F) << 4); 
}
else{
    *d++ |= (b & 0x0F); 
};

I’m looking specifically at the else statement and wondering in what order this occurs? I don’t have a regular C compiler, so I can’t test this. When we are performing *d++ |= (b & 0x0F);, what order does this occur in?

Answer 1

The ++ is applied on the pointer d, not on the lvalue that is being assigned to, *d.

If you really want to, you can think of it like this:

1. The value of b is bitwise-AND:ed with the constant 0x0f
2. The resulting bit pattern is bitwise-OR:ed into the value that d points at.
3. The pointer d is incremented to point at the next value.