> For the complete documentation index, see [llms.txt](https://boxlang.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://boxlang.ortusbooks.com/boxlang-+-++/modules/bx-spreadsheet/built-in-functions/isspreadsheetfile.md).

# IsSpreadsheetFile

Determines whether a file is a spreadsheet file.

## Method Signature

```
IsSpreadsheetFile(filepath=[any])
```

### Arguments

| Argument | Type  | Required | Description         | Default |
| -------- | ----- | -------- | ------------------- | ------- |
| `value`  | `ANY` | `true`   | The value to check. |         |

## Examples

Check if a value is a SpreadsheetFile fluent API object:

```js
// Check if object uses fluent API
var spreadsheet = new SpreadsheetFile();

if ( IsSpreadsheetFile( spreadsheet ) ) {
    println( "This is a fluent SpreadsheetFile object" );
}
```

Distinguish between BIF and fluent API:

```js
// BIF approach creates an object
var bifSpreadsheet = SpreadsheetNew();

// Fluent API approach
var fluentSpreadsheet = new SpreadsheetFile();

if ( IsSpreadsheetFile( fluentSpreadsheet ) ) {
    println( "Using fluent API" );
} else if ( IsSpreadsheetObject( bifSpreadsheet ) ) {
    println( "Using BIF approach" );
}
```

Validate for fluent chaining:

```js
// Ensure fluent API available for method chaining
function configureSpreadseet( obj ) {
    if ( IsSpreadsheetFile( obj ) ) {
        // Can use fluent API chaining
        return obj.addRow( [ "Header1", "Header2" ] )
                  .formatRow( 1, { bold = true } );
    }
    return obj;
}
```

## Related

* [IsSpreadsheetObject()](/boxlang-+-++/modules/bx-spreadsheet/built-in-functions/isspreadsheetobject.md) - Check for BIF spreadsheet objects
* [SpreadsheetFile Class](https://github.com/ortus-boxlang/boxlang-docs/tree/v1.x/boxlang-framework/boxlang-plus/modules/bx-spreadsheet/api-usage.md) - Fluent API documentation
* [SpreadsheetNew()](/boxlang-+-++/modules/bx-spreadsheet/built-in-functions/spreadsheetnew.md) - Create BIF spreadsheet
* [Type Checking Guide](https://github.com/ortus-boxlang/boxlang-docs/tree/v1.x/boxlang-framework/boxlang-plus/modules/bx-spreadsheet/type-checking.md) - BoxLang type validation


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