Which of the following describes a unary operator?

A unary operator is defined as an operator that operates on a single operand. This means it takes only one input value or variable and performs its operation, such as negation or incrementing a value. Common examples of unary operators in Java include the increment operator (++), the decrement operator (--), and the unary minus operator (-).

When you apply a unary operator, it directly modifies or evaluates a single value, which is fundamentally different from operators that work with two operands, such as binary operators (like addition or multiplication). The distinction is important in programming, as it clarifies how many values are involved in the operation and helps in understanding how to manipulate data within expressions. Therefore, the description that correctly defines a unary operator is the one that emphasizes its operation involving only a single operand.