---
url: >-
  /statelake/scripting-reference/functions-and-procedures/file-functions/changefileext.md
---

# ChangeFileExt

The **ChangeFileExt** function changes the extension on the given file path to that specified.

* The **Filename** parameter can be either a file name, or a complete file path.
* The **Extension** parameter should be given with the full-stop.

**Declaration**: Function ChangeFileExt( const FileName, Extension : string) : string

A basic example.

```pascal
procedure OnMapEvent(var Value:Variant);
begin
  Value := ChangeFileExt(Source.FileCon.CurrentFilename, '.dat');
end;
```

Some additional examples follow.

```pascal
procedure ScriptEvent (var Value : variant);
var
  f: string;
begin
  LogInfo('');
  f := 'abc.exe'; LogInfo('ExtractFileExt(''' + f + ''') -> ''' + ChangeFileExt(f, '.txt') + '''');
  f := 'C:\MyData\MyFiles\abc.exe'; LogInfo('ExtractFileExt(''' + f + ''') -> ''' + ChangeFileExt(f, '.jpg') + '''');
  f := 'abc.ref1.ref2.txt'; LogInfo('ExtractFileExt(''' + f + ''') -> ''' + ChangeFileExt(f, '.EXE') + '''');
  LogInfo('');
end;
```

The following portion of the log shows how the extension has been changed by the above code.