# Built-In Formulas

An explanation of the built-in formulas in SpreadJS, including code snippets

## Content

You can use built-in formulas in cells. Use the [formula](/spreadjs/api/classes/GC.Spread.Sheets.CellRange#formula) method or [setFormula](/spreadjs/api/classes/GC.Spread.Sheets.Worksheet#setFormula) method to add formulas. You can also specify the reference style with the `referenceStyle` property.

The following code sample sets the `referenceStyle` property in the **Workbook** method.

```javascript
spread.options.referenceStyle = GC.Spread.Sheets.ReferenceStyle.R1C1;
//spread.options.referenceStyle = GC.Spread.Sheets.ReferenceStyle.A1;
```

The following code sample uses the **formula** method.

```javascript
activeSheet.setValue(0,0,1);
activeSheet.setValue(0,1,2);
activeSheet.setValue(0,2,10);
activeSheet.getCell(1,1).formula("=SUM(A1:C1)");
```

To clear a formula from a cell or range, you have two primary options:

1.  `clear()`**:** Access this method via [GC.Spread.Sheets.Worksheet.clear()](https://developer.mescius.com/spreadjs/api/classes/GC.Spread.Sheets.Worksheet#clear ) or [GC.Spread.Sheets.CellRange.clear()](https://developer.mescius.com/spreadjs/api/classes/GC.Spread.Sheets.CellRange#clear). This action will clear both the formula and its associated calculated result, resulting in an empty cell.
2. `setFormula()`**:** Call the `setFormula()` method and pass `null` specifically for the formula argument. This will remove only the formula, retaining the cell's last computed value.

>type=note
> **Note:**
> Setting a new value in a formula-containing cell requires clearing the formula first. Failure to do so will prevent the new value from taking effect.

```javascript
sheet.setFormula(1, 1, '=SUM(A1,C3)');

sheet.setValue(1, 1, 7); // Failed

// Method1
sheet.getRange(1, 1, 1, 1).clear(GC.Spread.Sheets.StorageType.data);
// Method2
sheet.clear(1, 1, 1, 1, GC.Spread.Sheets.SheetArea.viewport, GC.Spread.Sheets.StorageType.data);
// Method3
sheet.setFormula(1, 1, null);

sheet.getFormula(1, 1, GC.Spread.Sheets.SheetArea.viewport);
// Output: null

sheet.setValue(1, 1, 7); // Success
```