✅ null reference
How do I fix possible null reference return do I add = null! after the errormessage or why does that come up as a warning?
```cs
using System;
using System.IO;
namespace Calculator.View
{
public class CalculatorView
{
public string ErrorMessage { get; set; }
public double ResultString { get; set; }
public string InputString { get; set; }
public string GetRPNString()
{
Console.WriteLine();
return Console.ReadLine();
}
public void DisplayResult(double result)
{
Console.WriteLine("Result: " + result);
}
public void DisplayError(string errorMessage)
{
Console.WriteLine("Error: " + errorMessage);
}
public string ReadInputFromFile(string filePath)
{
using (StreamReader reader = new StreamReader(filePath))
{
return reader.ReadLine();
}
}
public void WriteOutputToFile(string filePath, double result)
{
try
{
using (StreamWriter writer = new StreamWriter(filePath, false))
{
writer.WriteLine("Result: " + result);
}
Console.WriteLine($"Wrote result to file: {filePath}");
}
catch (Exception ex)
{
Console.WriteLine($"Error writing to file: {ex.Message}");
}
}
}
}
```
```cs
using System;
using System.IO;
namespace Calculator.View
{
public class CalculatorView
{
public string ErrorMessage { get; set; }
public double ResultString { get; set; }
public string InputString { get; set; }
public string GetRPNString()
{
Console.WriteLine();
return Console.ReadLine();
}
public void DisplayResult(double result)
{
Console.WriteLine("Result: " + result);
}
public void DisplayError(string errorMessage)
{
Console.WriteLine("Error: " + errorMessage);
}
public string ReadInputFromFile(string filePath)
{
using (StreamReader reader = new StreamReader(filePath))
{
return reader.ReadLine();
}
}
public void WriteOutputToFile(string filePath, double result)
{
try
{
using (StreamWriter writer = new StreamWriter(filePath, false))
{
writer.WriteLine("Result: " + result);
}
Console.WriteLine($"Wrote result to file: {filePath}");
}
catch (Exception ex)
{
Console.WriteLine($"Error writing to file: {ex.Message}");
}
}
}
}
```
