> 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/getting_started/hello_world.md).

# Hello world

A Sidef script can be written in any text editor and, by convention, it has the **`.sf`** extension.

The content of a simple *Hello World* program looks like this:

```ruby
#!/usr/bin/sidef

say "Hello, 世界";
```

If we save the content in a new file called **`hello.sf`**, we can execute the code by running:

```console
$ sidef hello.sf
```


---

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