How to format a string containing a dynamic number of elements?

Question

I am trying to format a string based on the elements received from the function calling it. This number of elements can varyfrom one to many.

Is there a way to call fmt.Sprintf with a variable number of elements. Something along the lines of:

receivedElements := []interface{}{"some","values"}
formattedString := fmt.Sprintf("Received elements: ...%s", receivedElements...)

Output: Received elements: some values

The capability of the `fmt` package is specified in its [documentation](https://golang.org/pkg/fmt/) and what you're looking for is not there, at least I wasn't able to find it. This means you'll have to write your own solution if passing the slice as is is not good enough. — mkopriva, Nov 28 '19 at 19:47
Also if all that bothers you are the square brackets around the values when you pass a slice to `fmt` you could always just slice those brackets away https://play.golang.com/p/eGBhnsXqWNO — mkopriva, Nov 28 '19 at 19:52

Nikita Leshchev · Accepted Answer · 2019-11-28T19:52:15.417

You can use https://golang.org/pkg/strings/#Repeat like that:

args := []interface{}{"some", "values"}
fmt.Println(fmt.Sprintf("values: " + strings.Repeat("%s ", len(args)), args...))

https://play.golang.org/p/75J6i2fSCaM

Or if you don't want to have last space in the line, you can create slice of %s and then use https://golang.org/pkg/strings/#Join

args := []interface{}{"some", "values"}
ph := make([]string, len(args))
for i, _ := range args {
    ph[i] = "%s"
}
fmt.Println(fmt.Sprintf("values: " + strings.Join(ph, ", "), args...))

https://play.golang.org/p/QNZT-i9Rrgn

How to format a string containing a dynamic number of elements?

1 Answers1