> 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/blob/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/blob/v1.x/boxlang-framework/boxlang-plus/modules/bx-spreadsheet/type-checking.md) - BoxLang type validation


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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://boxlang.ortusbooks.com/boxlang-+-++/modules/bx-spreadsheet/built-in-functions/isspreadsheetfile.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.