user3495562 user3495562 - 6 months ago 20
Java Question

How to input an integer's binary expression into a bitSet in java

How to input an integer's binary expression into a bitSet in java?

say

a = 15
I want put
1111
into a bitSet,

is there a function for this?

Answer

BitSet has a static valueOf(long[]) method which

Returns a new bit set containing all the bits in the given long array.

So an array with one long will have 64 bits, an array with two longs will have 128 bits, etc.

If you only need to get a BitSet from a single int value, use it like so

Integer value = 42;
System.out.println(Integer.toBinaryString(value));
BitSet bitSet = BitSet.valueOf(new long[] { value });
System.out.println(bitSet);

It prints

101010
{1, 3, 5}

In other words, from the right to left in the representation above, the 2nd, 4th, and 6th bit are set.