Determine if num is a power of two in java? [duplicate]

Question

Possible Duplicate:
How to check if a number is a power of 2

How could I write a method that would return true if passed in the value 2, 4, 8, 32, 64, and so on?

see bit twiddling hacks (and I'm sure this has been asked before on SO).... — Mitch Wheat
– Mitch Wheat, Commented Feb 5, 2012 at 4:17

David Schwartz · Accepted Answer · 2012-02-05 04:18:19Z

14

This is probably the best way:

((value & -value) == value)

answered Feb 5, 2012 at 4:18

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mk12 · Accepted Answer · 2012-02-05 04:18:05Z

Might want to look at this if you need a fast algorithm: