使用go-templates内的范围检测数组中的最后一项

Question

This program outputs simply

1,4,2,

but I would like to print

1,4,2.

As you can see the comma is printed after each items of an array.

package main

import "os"
import "text/template"

func main() {
    params := map[string]interface{}{
        "items": [3]int{1, 4, 2},
    }
    tpl := "{{range $i, $el := .items}}{{$el}},{{end}}"
    lister, _ := template.New("foo").Parse(tpl)
    lister.Execute(os.Stdout, params)
}

Is there a way to change {{range $i, $el := .items}}{{$el}},{{end}} and be sure that last item will print "." instead of ","

Answer 1

You can use

tpl := "{{range $i, $el := .items}}{{if $i}},{{end}}{{$el}}{{end}}."

to achieve that. The trick is to emit the comma separator first, but not for the first item in the range.