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Update Chapter02.dib

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Mark J Price 2023-07-19 08:18:31 +01:00
parent 2cfd8dad10
commit f827a14e78
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notebooks/Chapter02.dib
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@ -326,43 +326,6 @@ for (int i = 0; i < names.Length; i++)
#!markdown #!markdown
## Making a value type nullable
#!csharp
int thisCannotBeNull = 4;
// thisCannotBeNull = null; // compile error!
int? thisCouldBeNull = null;
Console.WriteLine(thisCouldBeNull);
Console.WriteLine(thisCouldBeNull.GetValueOrDefault());
thisCouldBeNull = 7;
Console.WriteLine(thisCouldBeNull);
Console.WriteLine(thisCouldBeNull.GetValueOrDefault());
#!markdown
## Checking for null
#!csharp
string authorName = null;
// the following throws a NullReferenceException
// int x = authorName.Length;
// instead of throwing an exception, null is assigned to y
int? y = authorName?.Length;
Console.WriteLine($"y is null: {y is null}");
// result will be 3 if authorName?.Length is null
var result = authorName?.Length ?? 3;
Console.WriteLine(result);
#!markdown
## Formatting using numbered positional arguments ## Formatting using numbered positional arguments
#!csharp #!csharp