# GetBaseBNFHash method

Gets a string hash calculated from the current Backus-Naur Form (BNF) grammar of the Qlik engine scripting language. If the hash changes between subsequent calls to this method, this indicates that the BNF grammar has changed.

## Parameters

| Name | Description | Mandatory | Type |
| --- | --- | --- | --- |
| qBnfType | The type of grammar to return:<br><br><ul><li>The script statements and the script functions if <em>qBnfType</em> is set to S.</li><li>The chart functions if <em>qBnfType</em> is set to E.</li></ul><br><br>One of:<br><br><ul><li>S or SCRIPT_TEXT_SCRIPT</li><li>E or SCRIPT_TEXT_EXPRESSION</li></ul> | Yes | String |

## Returns

| Name | Description | Type |
| --- | --- | --- |
| qBnfHash | A string hash of the BNF definition. | String |

## See also

[GetBaseBNF method](https://help.qlik.com/en-US/sense-developer/May2025/Subsystems/EngineJSONAPI/Content/service-Global-GetBaseBNF.htm)