Double question marks is a null coalescing operator. The ?? operator is called the null-coalescing operator. It returns the left-hand operand if the operand is not null; otherwise it returns the right hand operand.(msdn) there...
Double question marks is a null coalescing operator. The ?? operator is called the null-coalescing operator. It returns the left-hand operand if the operand is not null; otherwise it returns the right hand operand.(msdn) there...