The ?? operator is called null-coalescing operator.
This operator is used to provide a default value if the value of the operand on the left-hand side of the operator is null.
The usage is as follows: var variable = operand ?? default value;
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class Program
{
public int Value { get; set; }
public Program(int value)
{
Value = value;
}
static void Main(string[] args)
{
string input = GetName();
string name = input ?? "Alen Alex";
string inputAddress = GetAddress();
string address = inputAddress ?? "NA";
Program p1 = GetProgram();
Program p2 = p1 ?? new Program(10);
Console.WriteLine(name);
Console.WriteLine(address);
Console.WriteLine(p2.Value);
}
private static string GetAddress()
{
return "<<Proper Address>>";
}
private static Program GetProgram()
{
return null;
}
private static string GetName()
{
return null;
}
}
The output of this would be:
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Alen Alex
<<Proper Address>>
10
Reference: Microsoft Docs
