Can you explain what a parameter with the ability to pass multiple values is, and how it is used in functions or methods?

A parameter that allows passing multiple values is a function or method parameter that can accept a variable number of arguments. In Swift (iOS), this is implemented using variadic parameters, denoted by three dots (...).

For example, a function that takes any number of numbers and returns their sum:

func sum(numbers: Int...) -> Int {
    var total = 0
    for number in numbers {
        total += number
    }
    return total
}

let result = sum(numbers: 1, 2, 3, 4) // result will be 10

Such a parameter inside a function is treated as an array of the specified type, which makes it convenient to work with an arbitrary number of arguments.

This is useful when the number of values to be passed is unknown in advance and needs to be processed uniformly.