**<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.
Note: Initial data needs to be configured with loadUrl and loadSheetUrl parameters, while for collaborative editing, in addition to the configuration of loadUrl and loadSheetUrl, updateUrl and allowUpdate must be configured to take effect.
**<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...`.
