> For the complete documentation index, see [llms.txt](https://xlswriter-docs.viest.me/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xlswriter-docs.viest.me/english/helper/column-index-number-string-transform.md).

# Column index transform

## Number column index to string

```php
var_dump(\Vtiful\Kernel\Excel::stringFromColumnIndex(0));  // A
var_dump(\Vtiful\Kernel\Excel::stringFromColumnIndex(28)); // AC
```

## String column index to number

```php
var_dump(\Vtiful\Kernel\Excel::columnIndexFromString('A'));  // 0
var_dump(\Vtiful\Kernel\Excel::columnIndexFromString('AC')); // 28
```