C# nullable string error

Question

private string? typeOfContract
{
  get { return (string?)ViewState[\"typeOfContract\"]; }
  set { ViewState[\"typeOfContract\"] = value; }
}

Later

Answer 1

Please note that in upcoming version of C# which is 8, the answers are not true.

All the reference types are non-nullable by default and you can actually do the following:

public string? MyNullableString; 
this.MyNullableString = null; //Valid

However,

public string MyNonNullableString; 
this.MyNonNullableString = null; //Not Valid and you'll receive compiler warning. 

The important thing here is to show the intent of your code. If the "intent" is that the reference type can be null, then mark it so otherwise assigning null value to non-nullable would result in compiler warning.

More info

To the moderator who is deleting all the answers, don't do it. I strongly believe this answer adds value and deleting would simply keep someone from knowing what is right at the time. Since you have deleted all the answers, I'm re-posting answer here. The link that was sent regarding "duplicates" is simply an opening of some people and I do not think it is an official recommendation.