In Java, can I define an integer constant in binary format?

Question

Similar to how you can define an integer constant in hexadecimal or octal, can I do it in binary?

I admit this is a really easy (and stupid) question. My google sea

Answer 1

The answer from Ed Swangren

public final static long mask12 = 
  Long.parseLong("00000000000000000000100000000000", 2);

works fine. I used long instead of int and added the modifiers to clarify possible usage as a bit mask. There are, though, two inconveniences with this approach.

1. The direct typing of all those zeroes is error prone
2. The result is not available in decimal or hex format at the time of development

I can suggest alternative approach

public final static long mask12 = 1L << 12;

This expression makes it obvious that the 12th bit is 1 (the count starts from 0, from the right to the left); and when you hover mouse cursor, the tooltip

long YourClassName.mask12 = 4096 [0x1000]

appears in Eclipse. You can define more complicated constants like:

public final static long maskForSomething = mask12 | mask3 | mask0;

or explicitly

public final static long maskForSomething = (1L<<12)|(1L<<3)|(1L<<0);

The value of the variable maskForSomething will still be available in Eclipse at development time.