[youtubei.js](../../../../README.md) / [JsHelpers](../README.md) / memberBaseName # Function: memberBaseName() > **memberBaseName**(`memberExpression`, `source`): `string` \| `null` Defined in: [src/utils/javascript/helpers.ts:193](https://github.com/LuanRT/YouTube.js/blob/853a36307b5d644ada14dcb1216c2c22c2ae7b73/src/utils/javascript/helpers.ts#L193) Retrieves the base identifier for a member expression chain. ## Parameters ### memberExpression `MemberExpression` Member expression whose root should be resolved. ### source `string` Original source code for range lookups. ## Returns `string` \| `null`