c# - Finding the variable name passed to a function

Question

Let me use the following example to explain my question:

public string ExampleFunction(string Variable) {
    return something;
}

string WhatIsMyName = "Hello World";
string Hello = ExampleFunction(WhatIsMyName);

When I pass the variable WhatIsMyName to the ExampleFunction, I want to be able to get a string of the original variable's name. Perhaps something like:

Variable.OriginalName.ToString()

Is there any way to do this?

Answer 1

What you want isn't possible directly but you can use Expressions in C# 3.0:

public void ExampleFunction(Expression<Func<string, string>> f) {
    Console.WriteLine((f.Body as MemberExpression).Member.Name);
}

ExampleFunction(x => WhatIsMyName);

Note that this relies on unspecified behaviour and while it does work in Microsoft’s current C# and VB compilers, and in Mono’s C# compiler, there’s no guarantee that this won’t stop working in future versions.