C# new list add item
- C# list add item
- C# list add item to first position
- C# create new list and add item in one line
- C# list add item at index
- C# list add item if not exists
- C# list add item to last position
- C# list add items in constructor
- C# list add item specific index
- C# list add item to beginning
- C# list add item on top