What Are Variadic Functions in Go (... Syntax)

Variadic functions in Go accept a variable number of arguments by using the ... syntax in the parameter list, which the compiler treats as a slice of that type. You define the parameter with ...Type and access the arguments inside the function as a standard slice.

func sum(numbers ...int) int {
	total := 0
	for _, n := range numbers {
		total += n
	}
	return total
}

// Call with any number of integers
result := sum(1, 2, 3, 4, 5)

A variadic function is like a bucket that can hold any number of items of the same type, rather than requiring you to specify exactly how many slots it has. You use this when you need to pass a flexible list of values to a function without creating a slice first. It works just like passing a slice, but the syntax is cleaner for the caller.