Function extname

extname(path): string
Return the extension of the path with leading period (".").
Parameters
- path: string
  Path with extension.
Returns string
The file extension. E.g. returns .ts for file.ts.
Example: Usage
```
import { extname } from "@std/path/extname";
import { assertEquals } from "@std/assert";

if (Deno.build.os === "windows") {
  assertEquals(extname("C:\\home\\user\\Documents\\image.png"), ".png");
} else {
  assertEquals(extname("/home/user/Documents/image.png"), ".png");
}
```
Note: If you are working with file URLs, use the new version of extname from @std/path/unstable-extname.
- Defined in path/extname.ts:28