Is there a way to reuse an argument in fmt.Printf?

Question

I have a situation where I want to use my printf argument twice.

fmt.Printf("%d %d", i, i) 

Is there a way to tell fmt.Printf to just reuse the same i?

fmt.Printf("%d %d", i) 

Answer 1

You can use the [n] notation to specify explicit argument indexes like so:

fmt.Printf("%[1]d %[1]d\n", i) 

Here is a full example you can experiment with: http://play.golang.org/p/Sfaai-XgzN

Answer 2

Another option is text/template:

package main  import (    "strings"    "text/template" )  func format(s string, v interface{}) string {    t, b := new(template.Template), new(strings.Builder)    template.Must(t.Parse(s)).Execute(b, v)    return b.String() }  func main() {    i := 999    println(format("{{.}} {{.}}", i)) }