What's "|" mean in C# programming?

Question

I frequently read code like this:

System.Diagnostics.DebuggableAttribute.DebuggingModes.DisableOptimizations | System.Diagnostics.DebuggableAttribute.DebuggingModes.EnableEditAndContinue | System.Diagnostics.DebuggableAttribute.DebuggingModes.IgnoreSymbolStoreSequencePoints | System.Diagnostics.DebuggableAttribute.DebuggingModes.Default)

in C# program,sometimes parameter like this,what's this meanning ?

I have searched from google,but has no valuable answer,the '|' can not property parsing in Google engine,maybe i use the wrong way when searching.

when | is used as || it is OR operator and here it used as Enum values — donstack, Dec 08 '13 at 13:36
see [msdn](http://msdn.microsoft.com/ru-ru/library/kxszd0kx.aspx) — Grundy, Dec 08 '13 at 13:37

score 4 · Answer 1 · answered Dec 08 '13 at 13:35

4

'|' is the bitwise or operator, in this case it is used to create an enum value with all the given bits set.

DebuggingModes is a bitflag enumeration - this means each bit can indicate a flag and a single DebuggingModes value can be used to signal multiple flags.

Enums can be made bitflags using the BitFlagsAttribute:

[FlagsAttribute]
public enum DebuggingModes
{
   Default = 0,
   DisableOptimizations = 1,
   EnableEditAndContinue = 2,
   ...
}

answered Dec 08 '13 at 13:35

Lee

142,018
20
234
287

1

It depends. If you're comparing Booleans, it's a non-short-circuiting OR comparison (`||` is short-circuiting). For integral types (which includes enums), it's indeed the bitwise OR. – David S. Dec 08 '13 at 13:39

score 3 · Accepted Answer · answered Dec 08 '13 at 13:37

3

In this case it seems that it is a Flags enum

[Flags]
public enum Types
{
    None = 0,
    Type1 = 1,
    Type2 = 2,
    Type3 = 4,
}

So

Types someType = Types.Type1 | Types.Type2;

Would mean that it has both types.

answered Dec 08 '13 at 13:37

BrunoLM

97,872
84
296
452

score 1 · Answer 3 · answered Dec 08 '13 at 13:35

It is a bitwise OR operator iin C#. Here it is used to create an enum value with all the given set of bits.

Binary | operators are predefined for the integral types and bool. For integral types, | computes the bitwise OR of its operands. For bool operands, | computes the logical OR of its operands; that is, the result is false if and only if both its operands are false.

score 1 · Answer 4 · answered Dec 08 '13 at 13:36

It is a logical or operator. see here for a complete explanation.

Main explanation in the doc:

Binary | operators are predefined for the integral types and bool. For integral types, | computes the bitwise OR of its operands. For bool operands, | computes the logical OR of its operands; that is, the result is false if and only if both its operands are false.

score 0 · Answer 5 · answered Dec 08 '13 at 13:37

0

when | is used as || it is OR operator and here it used as Enum values

answered Dec 08 '13 at 13:37

donstack

2,557
3
29
44

What's "|" mean in C# programming?

5 Answers5