Default entity values

Used when returning default values from superValidate for an entity, or when a FormData field is empty.

type	value
string	""
number	0
boolean	false
object	{}
Array.isArray	[]
bigint	BigInt(0)
symbol	Symbol()

This whole behavior can be turned off if you pass options.implicitDefaults = false to superValidate, which means that you must add default to all required fields of your schema.

Non-supported defaults

Some Zod types like ZodEnum and ZodUnion can't use the above default values, so an exception will be thrown if you don't set a default value for them yourself, for example:

const schema = z.object({
  fish: z.enum(['Salmon', 'Tuna', 'Trout']).default('Salmon')
});

// If it's nullable/optional/nullish, no need for a default (but can still be set).
const schema = z.object({
  fish: z.enum(['Salmon', 'Tuna', 'Trout']).nullable()
});

Also, see this FAQ question if you need to set a value to something not included in the type.