Question

I have a 32-bit integer value and I want to translate that into two decimal values. One value from the 5 least significant bits and one decimal value from the rest of the bits (27 bits).

How would I do that in Java?

The only solution I can think of is something like this:


int i = 1073326082;
String binaryString = Integer.toBinaryString(i);
int fiveLeastSigValue = Integer.parseInt(binaryString.substring(27), 2));
int theRest = Integer.parseInt(binaryString.substring(0, 27), 2));


But im sure there is some more efficient way to do this. Any ideas?

Answer 1

Well, I’d imagine:

int value = ...;
int leastSignificant = value & 0x1f; // Bottom 5 bits
int mostSignificant = value >> 5; // Top 27 bits

Adjust the shift operator to “>>>” if you want to 0-extend (i.e. always have positive values).

I’m not sure what you mean by “partial decimal value” though – “decimal” is usually used to refer to non-integers, but you’re parsing integers. Is this what you want?