A **unary function** is a mathematical or programming function that takes exactly one argument. In programming, a unary function typically takes a single argument and produces a corresponding output.
**Let's explore a unary function with an example in JavaScript:**
**Example: Unary Function in JavaScript**
In this example, we have a unary function called `square` that takes a single argument `x`. The function calculates the square of the input number by multiplying `x` with itself and returns the result. When we call the function with `number` set to 5, it calculates the square (5 * 5) and returns 25, which is then printed to the console.
**Conclusion: **
As you can see, a **unary function** is a simple function that operates on a single argument, performing some computation, and returning the output. Unary functions are commonly used in various programming tasks, especially in functional programming paradigms, where operations on single values are frequent.

```
// Unary function to square a number
function square(x) {
return x * x;
}
// Usage of the unary function
const number = 5;
const result = square(number);
console.log(result); // Output: 25
```