boolean

A boolean value: true or false.

Signature

function boolean(msg?: Message): Schema<boolean>

Parameters

Parameter	Type	Description
msg	Message	Custom message. Replaces the default messages for all errors of this schema

Accepts

Only true and false. false is a valid value, not an empty one.

undefined, null and '' are treated as empty — see Empty values.

Error codes

Code	When	Default message
required	The value is empty	Required
boolean	Not true/false	Must be a boolean

You can change the texts: see Messages & i18n.

Checkboxes and query strings

A form checkbox is sent as "on", a query parameter as "true"/"1". Use coerce.boolean.

To require exactly true (e.g. "I accept the terms"), use literal(true).

Example

Newsletter subscription

const Settings = object({
  newsletter: optional(boolean(), false),
});

validate(Settings, {}).data;                   // { newsletter: false }
validate(Settings, { newsletter: true }).data; // { newsletter: true }

See also

• coerce.boolean
• literal — required consent