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The nameof expression - evaluate the text name of a symbol |
The C# `nameof` expression produces the name of its operand. You use it whenever you need to use the name of a symbol as text |
11/28/2022 |
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A nameof expression produces the name of a variable, type, or member as the string constant. A nameof expression is evaluated at compile time and has no effect at run time. When the operand is a type or a namespace, the produced name isn't fully qualified. The following example shows the use of a nameof expression:
[!code-csharp-interactivenameof expression]
You can use a nameof expression to make the argument-checking code more maintainable:
[!code-csharpnameof and argument check]
Beginning with C# 11, you can use a nameof expression with a method parameter inside an attribute on a method or its parameter. The following code shows how to do that for an attribute on a method, a local function, and the parameter of a lambda expression:
:::code language="csharp" source="snippets/shared/NameOfOperator.cs" id="SnippetNameOfParameter":::
A nameof expression with a parameter is useful when you use the nullable analysis attributes or the CallerArgumentExpression attribute.
When the operand is a verbatim identifier, the @ character isn't the part of a name, as the following example shows:
[!code-csharp-interactivenameof verbatim]
For more information, see the Nameof expressions section of the C# language specification, and the C# 11 - Extended nameof scope feature specification.