C# Language Preprocessor directives Conditional Expressions

Help us to keep this website almost Ad Free! It takes only 10 seconds of your time:
> Step 1: Go view our video on YouTube: EF Core Bulk Insert
> Step 2: And Like the video. BONUS: You can also share it!

Example

When the following is compiled, it will return a different value depending on which directives are defined.

// Compile with /d:A or /d:B to see the difference
string SomeFunction() 
{
#if A
    return "A";
#elif B
    return "B";
#else
    return "C";
#endif
}

Conditional expressions are typically used to log additional information for debug builds.

void SomeFunc()
{
    try
    {
        SomeRiskyMethod();
    }
    catch (ArgumentException ex)
    {
        #if DEBUG
        log.Error("SomeFunc", ex);
        #endif

        HandleException(ex);
    }
}


Got any C# Language Question?