NULL Conditional Operator In C# 6.0

Sometimes developers get the following exception: “object reference not set to an instance of an object”. Whenever we got such type of exception our mouth fell open but in C# 6 we can handle it easily using NULL Conditional Operator. So we can handle “System.NullReferenceException” using this operator. I am going to explain it with a very simple example where I am handling NullReferenceException for string datatype.

Null-Conditional operator (?.)

Before C# 6,

string name = null;
int length = name.Length;

It will throw the following error,



In C# 6.0

using static System.Console;

namespace BNarayan.NullConditionalOperator
{
    class Program
    {
        static void Main(string[] args)
        {
            string userName = "Banketeshvar Narayan";
            userName = null;
            if ((userName?.Length??0)>20)
            {
                WriteLine("UserName can not be more than 20 charcter long.");
            }
            else
            {
                WriteLine("UserName length is: {0}", userName?.Length??0);
            }
        }
    }
}

Output

 

If I comment the line userName = null; 

string userName = "Banketeshvar Narayan";
//userName = null;
if ((userName ? .Length ? ? 0) > 20)
{
    WriteLine("UserName can not be more than 20 charcter long.");
}
else
{
    WriteLine("UserName length is: {0}", userName ? .Length ? ? 0);
}

Output



I have tested the output for some statement in Immediate window which is as follows:

I have explained it in more details.

Must visit the above link it has more explanation.

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