# ext

Learn how to extract the file extension from a path.

Returns the file extension from a path, without the leading dot.

## Example

The following template prints the detected language based on a file extension:

**template.json5**

```json5
{
  "$schema": "https://schema.croct.com/json/v1/template.json",
  "title": "Language detector",
  "description": "Detects the language from a file path.",
  "options": {
    "file": {
      "type": "string",
      "description": "The path to a source file.",
      "default": "src/App.tsx"
    }
  },
  "actions": [
    {
      "name": "print",
      "message": "Detected language: ${ext(options.file) === 'ts' || ext(options.file) === 'tsx' ? 'TypeScript' : 'JavaScript'}"
    }
  ]
}
```

With the default value, `ext(options.file)` returns `tsx`, so the template prints `Detected language: TypeScript`.

## Parameters

- `path`: `string`

  The file path to extract the extension from.

## Return

The file extension without the leading dot.

For example, `ext('Button.tsx')` returns `tsx`. If the path has no extension, returns an empty string.

## Explore

- [Basename](/reference/cli/templates/functions/basename): Learn how to extract the filename from a path.
- [Dirname](/reference/cli/templates/functions/dirname): Learn how to extract the directory from a path.