Need help with debugging error CS0165 on C#

[Nav Faz]

Hi there, I am new to this forum and was referred to here by a kind redditor so I decided to come here to ask my question, basically, I was trying to make a to-do list console app using Java C#, however, while trying to use a string variable in a switch statement, I ran into error CS0165 which states that I am using an unassigned local variable. What does this error mean and how do I fix it?
PS: Here's the code from the program I was trying to write, I ran into an error at around the last line, would really appreciate any help or advice asap

class Program
    {
        static void Main(string[] args)
        {

            //booleans to be used

            bool newtask;
            bool completetask;
            bool motivateme;
            bool addquote;
            bool incompletedtasklist;
            bool incompletedtasknum;
            bool completedtasklist;
            bool completedtasknum;
            bool help;
            bool oops;





            //all variables to be used

            Int32 IncompletedTaskNum;
            Int32 CompletedTaskNum;
            string IncompletedTaskNames;
            string CompletedTaskNames;
            string MotivationalQuotes;
            string OopsQuotes;
            string CommandName;
            string NewTask = "newtask";

         


            //procedures for program

            Console.WriteLine("Hello User, what would you like to do today?");

            CommandName = Console.ReadLine();

            //if (CommandName == "newtask")
            //{
                //newtask = true;
            //}

            switch(CommandName)
            {
                
                case "newtask":
                    newtask = true;
                    Console.WriteLine("Please enter the name of this task.");
                    IncompletedTaskNames = Console.ReadLine();
                    break;
                case "completetask":
                    completetask = true;
                    Console.WriteLine("Please enter the name of the task that you have completed.");
                    CompletedTaskNames = Console.ReadLine();
                    break;
                case "motivateme":
                    motivateme = true;
                    Console.WriteLine("You can do it!");
                    Console.ReadLine();
                    break;
                case "addquote":
                    addquote = true;
                    Console.WriteLine("Please enter the quote that you would like to add.");
                    MotivationalQuotes = Console.ReadLine();
                    break;
                case "incompletedtasklist":
                    incompletedtasklist = true;
                    Console.WriteLine(IncompletedTaskNames);
                    break;
            }
        }
    }       
}

[Brennan Towry]

If you are talking about the line:

Console.WriteLine(IncompletedTaskNames);

You never initialized or assigned the variable, so when you give the Console the var, it will write null. Try this when you call the variable:

string IncompletedTaskNames = "";

or

string IncompletedTaskNames = null;

Also, just a side note, if you are trying to make a list (I infer from the "Names" part of your variable names), try looking into using an array, a list, or even a dictionary.

[Jesse Silverman]

Is Java C# something I am confused about or a Pure Typo??

[Stephan van Hulst]

No, Java C# is not a thing.

This is just plain old C#, so I'm removing it from the Java forums.

[Stephan van Hulst]

Nav, you really should not declare all your variables at the start of the method. It's not the 1970's. You should declare a variable when you first start using it.