New Features in C# 2.0—Nullable Types: What about
Microsoft .NET Framework, ASP.NET, Visual C# (CSharp, C Sharp, C-Sharp) Developer Training, Visual Studio
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What about…
…Boolean null values? How are they compared to correspond to the SQL three-value Boolean type?
C# provides two new operators:
bool? operator &(bool? x, bool? y) bool? operator |(bool? x, bool? y)
You can use these operators to create the truth table depicted in Table 1-1.
| If x is… | And y is… | x and y evaluate to… | x|y evaluates to… |
| True | True | True | True |
| True | False | False | True |
| True | Null | Null | True |
| False | True | False | True |
| False | False | False | False |
| False | Null | False | Null |
| Null | True | Null | True |
| Null | False | False | Null |
| Null | Null | Null | Null |
 
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