General-purpose languages provide set of operators—convenience constructs that behave like functions—and Swift is no different. You’ve already seen at least one such operator: +. Swift provides a wide range of built-in operators and allows you to define operators for your own classes and to extend built-in classes to add new operators.
Operators in Swift can be:
- Unary, which requires only one operand or input. (-a).
- Binary, which requires two operands or inputs. (a+b).
- Ternary, which requires three operands. (?:).
Operators come in one of three notations:
- Prefix, where the operator comes before the operand(s). The operator can be either unary or binary. (++a)
- Infix, where the operator requires two operands ...