Shortcut for creating single item list in C#

Question

Simply use this:

List<string> list = new List<string>() { "single value" };

You can even omit the () braces:

List<string> list = new List<string> { "single value" };

Update: of course this also works for more than one entry:

List<string> list = new List<string> { "value1", "value2", ... };

var list = new List<string>(1) { "hello" };

Very similar to what others have posted, except that it makes sure to only allocate space for the single item initially.

Of course, if you know you'll be adding a bunch of stuff later it may not be a good idea, but still worth mentioning once.

Michael's idea of using extension methods leads to something even simpler:

public static List<T> InList<T>(this T item)
{
    return new List<T> { item };
}

So you could do this:

List<string> foo = "Hello".InList();

I'm not sure whether I like it or not, mind you...

A different answer to my earlier one, based on exposure to the Google Java Collections:

public static class Lists
{
    public static List<T> Of<T>(T item)
    {
        return new List<T> { item };
    }
}

Then:

List<string> x = Lists.Of("Hello");

I advise checking out the GJC - it's got lots of interesting stuff in. (Personally I'd ignore the "alpha" tag - it's only the open source version which is "alpha" and it's based on a very stable and heavily used internal API.)

new[] { "item" }.ToList();

It's shorter than

new List<string> { "item" };

and you don't have to specify the type.

Use an extension method with method chaining.

public static List<T> WithItems(this List<T> list, params T[] items)
{
    list.AddRange(items);
    return list;
}

This would let you do this:

List<string> strings = new List<string>().WithItems("Yes");

or

List<string> strings = new List<string>().WithItems("Yes", "No", "Maybe So");

Update

You can now use list initializers:

var strings = new List<string> { "This", "That", "The Other" };

See http://msdn.microsoft.com/en-us/library/bb384062(v=vs.90).aspx

Yet another way, found on "C#/.Net Little wonders" (unfortunately, the site doesn't exist anymore):

Enumerable.Repeat("value",1).ToList()