Question

In the Go language,

[]string is a string array

and we also use ...string as a parameter.

What is the difference?

Function definition:

func f(args ...string) {}

Can I call this function like below?

args := []string{"a", "b"}

f(args)

Answer 1

[]string is a string array

Technically it’s a slice that references an underlying array

and we also use ...string as a parameter.

What is the difference?

With respect to the structure, nothing really. The data type resulting from both syntax is the same.

The ... parameter syntax makes a variadic parameter. It will accept zero or more string arguments, and reference them as a slice.

With respect to calling f, you can pass a slice of strings into the variadic parameter with the following syntax:

func f(args ...string) {
    fmt.Println(len(args))
}


args := []string{"a", "b"}

f(args...)

This syntax is available for either the slice built using the literal syntax, or the slice representing the variadic parameter (since there’s really no difference between them).

http://play.golang.org/p/QWmzgIWpF8