How this enum is assigned? What are all the value for each?
public enum SiteRoles
{
User = 1 << 0,
Admin = 1 << 1,
Helpdesk = 1 << 2
}
What is the use of assigning like this?
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Soner Gönül
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Billa
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Because the answers already explain it in better detail I leave this as a comment: `1 << X` is the same thing as doing `2^X` in math (where `^` is the power symbol not the XOR symbol) so you are assigning the values `2^0`, `2^1`, `2^2` – Scott Chamberlain Nov 27 '13 at 14:30
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Often used in conjunction with `[Flags]` attribute, relevant http://stackoverflow.com/q/8447/841176 – Konstantin Nov 27 '13 at 14:32
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More generally `X < – Scott Chamberlain Nov 27 '13 at 14:45
1 Answers
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They're making a bit flag. Instead of writing the values as 1, 2, 4, 8, 16, etc., they left shift the 1 value to multiply it by 2. One could argue that it's easier to read.
It allows bitwise operations on the enum value.
1 << 0 = 1 (binary 0001)
1 << 1 = 2 (binary 0010)
1 << 2 = 4 (binary 0100)
dee-see
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`bitshift operator` how do i understand this? I dont know how to read this statement `User = 1 << 0` and use it – Billa Nov 27 '13 at 14:27
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LOL - it could certainly be easier to count if there are large enumerations. That's a neat trick, @Billa. I'll have to remember that one. – jp2code Nov 27 '13 at 14:27
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Bit shift operator. `1 << 0` is really `0001`. `1 << 1` is `0010`, etc. – jp2code Nov 27 '13 at 14:28
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2`One could argue that it's easier to read` .. one could also argue that it wasn't :) – Jens Kloster Nov 27 '13 at 14:29
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3@JensKloster For sure, that's why I didn't go straight for a "it's easier to read" haha – dee-see Nov 27 '13 at 14:30