**<spanstyle="font-size:20px;">A</span>**: Use one-dimensional array format [celldata](/zh/guide/sheet.html#celldata), after the initialization is completed, the data converted into a two-dimensional array format is used for storage and update, and celldata is no longer used.
If you need to take out data as initial data, you need to execute `luckysheet.getGridData(data)` to convert it to celldata data.
Among them, the celldata in `{ r, c, v }` format is converted to a two-dimensional array using `luckysheet.buildGridData(luckysheetfile)`, and the input parameter is the table data object `luckysheetfile`
Summarized as follows:
```js
// data => celldata two-dimensional array data is converted into {r, c, v} format one-dimensional array, the input parameter is two-dimensional data
luckysheet.getGridData(data)
// celldata => data The two-dimensional array required to generate the table, the input parameter is the table data object file
**<spanstyle="font-size:20px;">A</span>** : Refer to [Table data format](/zh/guide/sheet.html#calcchain) ,just set the calcChain corresponding to the cell data.
**<spanstyle="font-size:20px;">A</span>**: [loadUrl](/zh/guide/config.html#loadurl). Configure loadUrl, Luckysheet will request the entire table data through ajax, and updateUrl will be used as the interface address for collaborative editing in real-time saving.
**<spanstyle="font-size:20px;">A</span>**: Each sheet page has a unique id, which is `index`, which can be incremented by numbers or a random string. And `order` is the sorting situation of all sheets, starting from 0, can only be numbers `0,1,2...`.
