Write a function to join the strings and add it to the templatefunc map:

func join(sep string, s ...string) string {    return strings.Join(s, sep)}

Add the function to template before parsing:

t, err := template.New(name).Funcs(template.FuncMap{"join": join}).Parse(text)

Use it in the template like this:

{{$x := join ", " "hello" "world"}}

playground example

I assign to variable$x to show how use the function result in a template expression. The result can be used directly as an argument to another function without assigning to a variable.

Here's a version of the function that works with slices instead of variadic arguments:

func join(sep string, s []string) string {    return strings.Join(s, sep)}

Use it like this where. is a slice:

{{$x := join ", " .}}

playground example.

If your goal is to join two strings directly do the output, then then use{{a}}sep{{b}} wherea andb are the strings andsep is the separator.

Use range to join a slice to the output. Here's an example that joins slice. with separator", ".:

{{range $i, $v := .}}{{if $i}}, {{end}}{{$v}}{{end}}

playground example.

Use a combination ofdelimit andslice, e.g.

{{ delimit (slice "foo" "bar" "buzz") ", " }}<!-- returns the string "foo, bar, buzz" -->

Originally from thegohugo docs

Here is how I joined two strings in go template language (this is within a Helm template for Kubernetes). In this case I am creating a host name using go'sprintf function:

host: {{ printf "%v%v" "my-super" ".apps.my.org" }}

Put in a%v for each value.

The output is:

host: my-super.apps.my.org

You can put spaces between the%v values, or commas, or whatever -- check with go's string format options for more, um, options!

In the template examplehttps://golang.org/src/text/template/example_test.go they show you how to do this.

In summary:

var funcs = template.FuncMap{"join": strings.Join}...masterTmpl, err := template.New("master").Funcs(funcs).Parse(master)

There's some other neat tricks in the example too.

Variable Overwrite Gotcha

In case anyone else is trying to 'join' potentially-empty strings with a separator, beware:= vs=. The latter is for updating a variable.

{{- $path := .Values.fileName -}}{{- if .Values.folder }}{{-   $path = print .Values.folder "/" $path }}{{- end }}

Using$path := .. inside the if will create a new variable scoped to the if statement.

• string
• go-templates