# Reader

The reader opens an existing XLSX and exposes its data either in full (load all rows into an array) or via a cursor (one row at a time, constant memory). It also surfaces sheet metadata — styles, merged cells, hyperlinks, validations, conditional formats, page setup, defined names, images, comments and charts.

Reader features require the extension to be built with `--enable-reader` (the default in PECL packages).

Pages in this section:

* Iteration: [worksheet list](/english/reader/sheet_list.md), [worksheet list with metadata](/english/reader/sheet-list-with-meta.md), [full read](/english/reader/read-file-full.md), [cursor read](/english/reader/read-file-cursor.md), [cell callback mode](/english/reader/cell_callback.md)
* Filtering: [skip empty cells](/english/reader/skip-empty-cells.md), [skip empty rows](/english/reader/skip-empty-row.md), [set global type](/english/reader/set-type.md), [read by data type](/english/reader/data-type.md), [data type constants](/english/reader/data-type-const.md)
* Cell-level: [next row with formula](/english/reader/next-row-with-formula.md), [next row with rich text](/english/reader/next-row-rich.md), [read style format](/english/reader/get-style-format.md)
* Sheet-level metadata: [merged cells](/english/reader/get-merged-cells.md), [hyperlinks](/english/reader/get-hyperlinks.md), [sheet protection](/english/reader/get-sheet-protection.md), [row / column options](/english/reader/row-column-options.md), [conditional formats](/english/reader/get-conditional-formats.md), [data validations](/english/reader/get-data-validations.md), [auto filter](/english/reader/get-auto-filter.md), [defined names](/english/reader/get-defined-names.md), [page setup](/english/reader/get-page-setup.md), [formula AST](/english/reader/get-formula-ast.md)
* Embedded objects: [iterate images](/english/reader/iterate-images.md), [iterate comments](/english/reader/iterate-comments.md), [iterate charts](/english/reader/iterate-charts.md)


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://xlswriter-docs.viest.me/english/reader.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.