Returning the x'th bit of of n(int, string,...)

Question

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Java: Checking if a bit is 0 or 1 in a long

I want to return the x'th bit of n. Bit 0 is least significant bit. i need a method like public static int getBit(int n, int i) that get n and return the i'th bit.

You haven't stated whether getBit should return `0` and`1`, `0` and `1 << n` — Peter Lawrey, Aug 08 '12 at 08:49

Peter Lawrey · Answer 1 · 2012-08-08T08:50:25.603

1

Do you mean?

 public static int getBit(int n, int i) {
     return (n >>> i) & 1
 }

or as @harold suggests

 n & (1L << x)

edited Aug 08 '12 at 08:50

answered Aug 08 '12 at 08:25

Peter Lawrey

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score 1 · Answer 2 · answered Aug 08 '12 at 08:25

1

return (1L << x) & n;

should work just fine.

answered Aug 08 '12 at 08:25

Zéychin

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Or `1L` if n is a `long` – Peter Lawrey Aug 08 '12 at 08:28
You're right, because the datatype wasn't specified. I'll edit that in now. – Zéychin Aug 08 '12 at 08:29
That will work even if the type is not `long` ;) – Peter Lawrey Aug 08 '12 at 08:30
Exactly right. I had just answered for the general `int` datatype case. – Zéychin Aug 08 '12 at 08:31

Returning the x'th bit of of n(int, string,...)

2 Answers2