> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/s/string_interpolation_included.md).

# String interpolation included

```ruby
var extra = 'little'
say "Mary had a #{extra} lamb"
```

or:

```ruby
say ("Mary had a %s lamb" % 'little')
```

See: [documentation](https://github.com/trizen/sidef/wiki#strings)