C# extension method, get rid of ref keyword

I have written a little extension method to add a value to the beginning of a List.

Here is the code;

public static class ExtensionMethods
{
    public static void AddBeginning<T>(this List<T> item, T itemValue, ref List<T&开发者_运维百科gt; currentList)
    {
        List<T> tempList = new List<T> {itemValue};
        tempList.AddRange(currentList);
        currentList = tempList;
    }
}

So that I can add the value to the beginning of the list, I have to use the ref keyword.

Can anybody suggest have to amend this extension method to get rid of the ref keyword?

You can just call currentList.Insert(0, itemValue); to insert into the beginning.

Edit:

Note - this code will modify the list instance whereas the original code left the list intact and produced a new list with the additional data inserted at the beginning.

public static void AddBeginning<T>(this List<T> currentList, T itemValue)
{
    currentList.Insert(0, itemValue);
}

It really helps to read the docs for the class you're using.

Also, I would suggest just using Insert directly, instead of this extension method.

Use the List Insert method and supply the index that you want the new value (0) added at?