Determining number of elements in a bitset?

Question

Neither size() or length() returns the number of bits in the set, so how do I iterate over a bitset?
Bitset bs = new Bitset(10);
bs.set(3,true);
bs.size(); // returns 64 -- who cares about the memory used? Does the JVM even really know?
bs.length(); // returns 4
int i=0;
for(; i<10; i++)
etc...
Is there a method I'm overlooking to return the number of elements in the bitset?
Thx, Chris

Answer 1

Such info is not stored in the bitset object, as you can see reading the source code of java.util.BitSet.
As you can read in the source code, the better you can go is getting the 'logical length' with the method 'length'.
See that 'nbits' is not stored anywhere.
    public BitSet(int nbits) {
     // nbits can't be negative; size 0 is OK
     if (nbits < 0)
         throw new NegativeArraySizeException("nbits < 0: " + nbits);
     bits = new long[(unitIndex(nbits-1) + 1)];
    }