Changing a variable changes also another variable. Prevent variables having the same reference

I have a class that the constructor requires a class and other things like:

public class SomeClass<T>
{
    //global private variables for class
    List<T> originalList = new List<T>;
    List<T> tempList = new List<T>;

    public SomClass(List<T> listParam, string name, ..etc)
    {
        originalList = listParam;
        tempList = listParam;

        originalList.removeAt(0);  // this also removes an item from tempList.


    }
}

I know this is because originalList and tempList have the same reference. How could I make them have diferent refer开发者_如何转开发ences. I use the tempList to filter results and whenever I want to refresh I use the originalList

You could make a copy of listParam, rather than just assigning its reference:

tempList = listParam.ToList();

Note that this does not create a copy of each object in the list, but just a copy of the references to those objects.

Instead of accepting a List<T>, accept an IEnumerable<T>. If you then want a concrete list, call .ToList() on it.

The original source is unaffected, and you have a copy. You also have the benefit of being able to take anything that supports the interface.

Edit: I misread the code in the question, your copy is in the same class. Well, it's in two places, the class and the caller. I stand by my suggestion, but yes, you'd need two invocations of .ToList(), one for each copy.