Conditional Operator / Ternary Operator : condition ? true_expression : false_expression; bool x = condition ? true : false; eg : string result = (percentage >= 36) ? "pass" : "fail" ; -------------------------------------------------------- NullCoalesce (??) int totalMarks = marks ?? 0 ; 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. eg: int ? x = null ; int y = x ?? -1; int? is a shorthand for Nullable, which itself is shorthand of Nullable. eg Nullable a = null; A nullable type can represent the correct range of values for its underlying value type, plus a additional null value. --------------------------------------------------------