Initializing ArrayList with constant literal

MandoMando picture MandoMando · Nov 12, 2009 · Viewed 64.8k times · Source

Can the ArrayList below be initialized directly without the need for aFileExt string array?

private static string[] aFileExt = 
     {"css", "gif", "htm", "html", "txt", "xml" };
private System.Collections.ArrayList alFileTypes =
     new System.Collections.ArrayList(aFileExt);

The line below is the goal, but my .Net Compiler does not like it:

private static System.Collections.ArrayList alFileTypes = 
     new System.Collections.ArrayList({"css","gif","htm","html","txt","xml"});

I am using the .net Micro Framework and thus do not have access to generic types.

Answer

Jon Skeet picture Jon Skeet · Nov 12, 2009

C# 1 or 2:

private static ArrayList alFileTypes = 
     new ArrayList(new string[] {"css","gif","htm","html","txt","xml"});

C# 3 using an implicitly typed array:

private static ArrayList alFileTypes = 
    new ArrayList(new[] {"css","gif","htm","html","txt","xml"});

C# 3 using a collection initializer:

private static ArrayList alFileTypes = 
    new ArrayList{"css","gif","htm","html","txt","xml"};

Or create your own helper method:

public static ArrayList CreateList(params object[] items)
{
    return new ArrayList(items);
}

then:

static ArrayList alFileTypes = CreateList("css","gif","htm","html","txt","xml");

Any reason why you're not using the generic collections, btw?