Java Iterate Bits in Byte Array

java arrays byte bit loops
Hamza Yerlikaya picture Hamza Yerlikaya · Jun 23, 2009 · Viewed 50k times · Source

How can i iterate bits in a byte array?

Answer

Jon Skeet picture Jon Skeet · Jun 23, 2009

You'd have to write your own implementation of Iterable<Boolean> which took an array of bytes, and then created Iterator<Boolean> values which remembered the current index into the byte array and the current index within the current byte. Then a utility method like this would come in handy:

private static Boolean isBitSet(byte b, int bit)
{
    return (b & (1 << bit)) != 0;
}

(where bit ranges from 0 to 7). Each time next() was called you'd have to increment your bit index within the current byte, and increment the byte index within byte array if you reached "the 9th bit".

It's not really hard - but a bit of a pain. Let me know if you'd like a sample implementation...

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