Java: number of bit bits set in java.util.BitSet

Question

Any quick way to count the number of bits in a bitNetwork other than the usual method of "keeping a counter"?

Answer 1

The cardinality () method returns the number of bits set.

Answer 2

(Assuming you don't want to call power ())

int count = 0; for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) { count++; } 

see javadoc

Answer 3

 BitSet B1 = new BitSet(3); B1.set(0); B1.cardinality(); 

Output:

 1