Minimalist array creation in c#

Question

I've always wanted to be able to use the line below but the C# compiler won't let me. To me it seems obvious and unambiguos as to what I want.

myString.Trim({'[', ']'});

I can acheive my goal using:

myString.Trim(new char[]{'[', ']'});

So I don't die wondering is there any other way to do it that is closer to the first approach?

Answer 1

The string.Trim(...) method actually takes a params argument, so, why do you not just call:

myString.Trim('[', ']');

Answer 2

This will work too ...

myString.Trim( '[',']' );

Note the params declaration in the defition of Trim, it let's you pass as many arguments as you want and takes them as an array.

Answer 3

You could also try this:

myString.Trim("[]".ToCharArray());

Answer 4

Others have concentrated on the specific example (and using the fact that it's a parameter array is the way to go), but you may be interested in C# 3's implicit typing. You could have written:

myString.Trim(new[] {'[', ']'});

Not quite as compact as you were after, as you still need to express the concept of "I want to create an array" unless you're writing a variable initializer, but the type of the array is inferred from the contents.

The big use case for this is anonymous types:

var skeets = new[] {
   new { Name="Jon", Age=32 },
   new { Name="Holly", Age=33 },
   new { Name="Tom", Age=5 },
   new { Name="Robin", Age=3 },
   new { Name="William", Age=3 }
};

Here you couldn't write the name of the type, because it doesn't have a name (that's expressible in C#).

One other point to make about your specific example - if you're going to use this frequently (i.e. call the Trim method often) you may want to avoid creating a new array each time anyway:

private static readonly char[] SquareBrackets = {'[', ']'};

public void Whatever() {
    ...
    foo = myString.Trim(SquareBrackets);
    ...
}