Checking bits in a bitwise operation

I'm working on a homework assignment, and this specific part of it is confusing me:

Then use masking and shifting operations to decode the number. For each of the four possible diagnostics, mask off the right-hand bit. If it is 1, set the corresponding level variable to true. Then right-shift one bit and repeat.

My only problem is that I don't know how to refer to this specific bit and check it. I tried doing this:

Code:

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if (arg[0] == 0b1)
          boolVar = true;
arg = arg >> 1;
//repeat for other bits

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and learned that apparently you can't treat a number in this case like an array. So how would I be able to refer to this bit?

http://cboard.cprogramming.com/c-pro...ml#post1178251

Code:

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int a = 3;

//test if Low Order bit is true
if( a & 1)cout << "Least significant bit is 1\n";

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what happens here is the value stored in a 0000 0011 is bitwise-anded with 0000 0001 which returns 0000 0001. which is true!