In C# what does it mean when you have a variable and an &?

Question

Found some code online I was looking at to solve a problem, and I'm not exactly sure what it's doing where it says "(candidate & 1) == 0". candidate is an int.

 if ((candidate & 1) == 0)
            {
                if (candidate == 2)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }

It's a bitwise operator https://msdn.microsoft.com/en-us/library/17zwb64t.aspx — hardkoded, Jun 19 '17 at 13:36
https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/and-operator — Ry-, Jun 19 '17 at 13:36
`if ((candidate & 1) == 0)` is checking if `candidate` is odd or even, doing a bitwise `AND` operation — Pikoh, Jun 19 '17 at 13:39

adjan · Answer 1 · 2017-06-19T13:43:47.967

2

It's the binary (bitwise) AND operator. In your case the if statement is checking whether the least significant bit is 1, or in other words, whether candidate is even:

Example using numbers 35 and 34:

35 & 1 = 0b100011 & 0b1 == 1 => odd
34 & 1 = 0b100010 & 0b1 == 0 => even

See also: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/and-operator

edited Jun 19 '17 at 13:43

answered Jun 19 '17 at 13:36

adjan

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In C# what does it mean when you have a variable and an &?

1 Answers1