--- title: boolean --- For options where the choice is either `true` or `false`, **on** or **off**, or **yes** or **no**, use a boolean option. ## Structure A boolean option is a plain object with these properties: - `bool` : Either `true` or `false` which will be the default - `hide` (optional) : A method to [control the optional display of the option][hide] [hide]: /reference/api/config/options#optionally-hide-options-by-configuring-a-hide-method ## Example ```js options: { withLining: { bool: true } } ```