is there in C# a method for List like resize in c++ for vector

Question

When I use resize(int newsize) in C++ for vector, it means that the size of this vector are set to newsize

Answer 1

Just to make Jon Hanna's answer more readable:

public static class ListExtras
{
    //    list: List to resize
    //    size: desired new size
    // element: default value to insert

    public static void Resize(this List list, int size, T element = default(T))
    {
        int count = list.Count;

        if (size < count)
        {
            list.RemoveRange(size, count - size);
        }
        else if (size > count)
        {
            if (size > list.Capacity)   // Optimization
                list.Capacity = size;

            list.AddRange(Enumerable.Repeat(element, size - count));
        }
    }
}