Unary function


A unary function is a function that takes one argument. A unary operator belongs to a subset of unary functions, in that its range coincides with its domain.

Examples

The successor function, denoted, is a unary operator. Its domain and codomain are the natural numbers, its definition is as follows:
In many programming languages such as C, executing this operation is denoted by postfixing to the operand, i.e. the use of is equivalent to executing the assignment.
Many of the elementary functions are unary functions, in particular the trigonometric functions, logarithm with a pre-specified base, exponentiation to a pre-specified power or of a pre-specified base, and hyperbolic functions are unary.