C# null coalescing operator returning null

Question

Recently my co-worker showed me a block of code that was not working correctly:

public class SomeClass
{
    private IList _categories;

    publ         


        

Answer 1

If you sure that its because of threading issue, then use the lock keyword. I believe this should work.

public class SomeClass
{
    private IList _categories;

    public void SetCategories()
    {
        lock(this) 
        {
          _categories = GetCategories() ?? new List();
          DoSomethingElse();
        }
    }

    public IList GetCategories()
    {
        return RetrieveCategories().Select(Something).ToList();
    }
}