Does .NET have an equivalent of **kwargs in Python?

Question

I haven't been able to find the answer to this question through the typical channels.

In Python I could have the following function definition

def do_the_needful(**kwargs):
    # Kwargs is now a dictionary
    # i.e. do_the_needful(spam=42, snake='like eggs', spanish='inquisition')
    # would produce {'spam': 42, 'snake': 'like eggs', 'spanish': 'inquisition' }

I know .NET has the ParamArray, which produces a sequence of unnamed arguments, similar to the *args syntax in Python... Does .NET have an equivalent of **kwargs, or something similar?

I only know the anonymous type hack where you write `do_the_neeful(new{spam=43})` and then extract the properties through reflection. — CodesInChaos, Apr 24 '13 at 20:36

perror · Accepted Answer · 2023-02-03T11:15:37.877

So, unfortunately, there is no way of simulating the Python **kwargs in C#. You will always loose parameter names in the process (see comment by @alelom below).

But, it seems that what you look for is a variadic function. If you want to know how to implement it in various programming languages, the best is to look at the Wikipedia page about it.

So, according to the Wikipedia, implementing a variadic function in C# and VisualBasic is done like this:

Other languages, such as C#, VB.net, and Java use a different approach—they just allow a variable number of arguments of the same (super)type to be passed to a variadic function. Inside the method they are simply collected in an array.

C# Example
public static void PrintSpaced(params Object[] objects)
{
    foreach (Object o in objects)
        Console.Write(o + " "); 
}    
// Can be used to print: PrintSpaced(1, 2, "three");
VB.Net example
Public Shared Sub PrintSpaced(ParamArray objects As Object())
    For Each o As Object In objects
        Console.Write(o & " ")
    Next
End Sub
' Can be used to print: PrintSpaced(1, 2, "three")

C#/VB, and according to Wikipedia - nope, just the param only variety. — Wayne Werner, Apr 25 '13 at 03:20
Agree with @DmitriySintsov -- this answer is wrong, because `params` replicates the `*args` behaviour, not the `**kwargs` behaviour. You lose the parameter names with C#'s `params` keyword. From what I could gather, there is no built-in way to obtain the `**kwargs` behaviour in C# :( — alelom, Jan 15 '23 at 08:41

Does .NET have an equivalent of **kwargs in Python?

1 Answers1

C# Example

VB.Net example

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