Is there something wrong with BitArrays in C#?

Question

When I conpile this code:

BitArray bits = new BitArray(3);
bits[0] = true;
bits[1] = true; 
bits[2] = true;
BitArray moreBits = new BitArray(3);
bits[0] = true;
bits[1] = true;
bits[2] = true;
BitArray xorBits = bits.Xor(moreBits);
foreach (bool bit in xorBits)
{
Console.WriteLine(bit);
}

I get the following output:

True True True

When I do an xor on two boolean values by saying true ^ true i get false.

Is there something wrong with the code. My memory of the truth table for XOR was that True XOR True is false.

• Keith: Frameworks like C#'s or Java's are almost never at fault because so many other people are using them and testing them. Always check your own code first. In this case Kent's answer covers it.
• Omar Kooheji: yeah I tried to delete the question once I'd noticed that but because his answer has been voted up I can't delete it. Somone else close it.
• Omar Kooheji: Why is this getting up voted?
• Fredou: you can close your own question
• Omar Kooheji: No you can votw to close it, but not close it... I need 3 more votes. and it's been upvoted again... I despair... do people actually read questions? At least Kent got a good answer badge for spotting my idiocy...

Answer 1

Copy and paste error.

BitArray moreBits = new BitArray(3);
bits[0] = true;
bits[1] = true;
bits[2] = true;

That should be:

BitArray moreBits = new BitArray(3);
moreBits[0] = true;
moreBits[1] = true;
moreBits[2] = true;

• Eight-Bit Guru: Been there, done that. And it's not an error you make once, early in your career, and never repeat - copy/paste gremlins lurk forever behind your monitor, just waiting for a momentary lapse in concentration. ;)

Answer 2

You are setting bits to true twice. You are not settings moreBits to true, so it defaults to all-false. I blame copy/paste!

EDIT: in the short time it took me to write this Kent answered and got upvoted 8 times!