# nonOptional

> This document is the Markdown version of [valibot.dev/api/nonOptional/](https://valibot.dev/api/nonOptional/). For the complete documentation index, see [llms.txt](https://valibot.dev/llms.txt).

Creates a non optional schema.

> This schema function can be used to override the behavior of [`optional`](/api/optional.md).

```ts
const Schema = v.nonOptional<TWrapped, TMessage>(wrapped, message);
```

## Generics

- `TWrapped` `extends BaseSchema<unknown, unknown, BaseIssue<unknown>>`
- `TMessage` `extends ErrorMessage<NonOptionalIssue> | undefined`

## Parameters

- `wrapped` `TWrapped`
- `message` `TMessage`

### Explanation

With `nonOptional` the validation of your schema will not pass `undefined` inputs. If the input is `undefined`, you can use `message` to customize the error message.

## Returns

- `Schema` `NonOptionalSchema<TWrapped, TMessage>`

## Examples

The following examples show how `nonOptional` can be used.

### Non optional string

Schema that does not accept `undefined`.

```ts
const NonOptionalStringSchema = v.nonOptional(v.optional(v.string()));
```

### Unwrap non optional

Use [`unwrap`](/api/unwrap.md) to undo the effect of `nonOptional`.

```ts
const NonOptionalNumberSchema = v.nonOptional(v.optional(v.number()));
const OptionalNumberSchema = v.unwrap(NonOptionalNumberSchema);
```

## Related

The following APIs can be combined with `nonOptional`.

### Schemas

[`any`](/api/any.md), [`array`](/api/array.md), [`bigint`](/api/bigint.md), [`blob`](/api/blob.md), [`boolean`](/api/boolean.md), [`custom`](/api/custom.md), [`date`](/api/date.md), [`enum`](/api/enum.md), [`exactOptional`](/api/exactOptional.md), [`file`](/api/file.md), [`function`](/api/function.md), [`instance`](/api/instance.md), [`intersect`](/api/intersect.md), [`lazy`](/api/lazy.md), [`literal`](/api/literal.md), [`looseObject`](/api/looseObject.md), [`looseTuple`](/api/looseTuple.md), [`map`](/api/map.md), [`nan`](/api/nan.md), [`never`](/api/never.md), [`nonNullable`](/api/nonNullable.md), [`nonOptional`](/api/nonOptional.md), [`null`](/api/null.md), [`nullable`](/api/nullable.md), [`nullish`](/api/nullish.md), [`number`](/api/number.md), [`object`](/api/object.md), [`objectWithRest`](/api/objectWithRest.md), [`optional`](/api/optional.md), [`picklist`](/api/picklist.md), [`promise`](/api/promise.md), [`record`](/api/record.md), [`set`](/api/set.md), [`strictObject`](/api/strictObject.md), [`strictTuple`](/api/strictTuple.md), [`string`](/api/string.md), [`symbol`](/api/symbol.md), [`tuple`](/api/tuple.md), [`tupleWithRest`](/api/tupleWithRest.md), [`undefined`](/api/undefined.md), [`undefinedable`](/api/undefinedable.md), [`union`](/api/union.md), [`unknown`](/api/unknown.md), [`variant`](/api/variant.md), [`void`](/api/void.md)

### Methods

[`assert`](/api/assert.md), [`config`](/api/config.md), [`fallback`](/api/fallback.md), [`getDefault`](/api/getDefault.md), [`getDefaults`](/api/getDefaults.md), [`getFallback`](/api/getFallback.md), [`getFallbacks`](/api/getFallbacks.md), [`is`](/api/is.md), [`message`](/api/message.md), [`parse`](/api/parse.md), [`parser`](/api/parser.md), [`pipe`](/api/pipe.md), [`safeParse`](/api/safeParse.md), [`safeParser`](/api/safeParser.md), [`unwrap`](/api/unwrap.md)

### Actions

[`check`](/api/check.md), [`brand`](/api/brand.md), [`description`](/api/description.md), [`flavor`](/api/flavor.md), [`guard`](/api/guard.md), [`metadata`](/api/metadata.md), [`partialCheck`](/api/partialCheck.md), [`rawCheck`](/api/rawCheck.md), [`rawTransform`](/api/rawTransform.md), [`readonly`](/api/readonly.md), [`title`](/api/title.md), [`transform`](/api/transform.md)

### Utils

[`entriesFromList`](/api/entriesFromList.md), [`isOfKind`](/api/isOfKind.md), [`isOfType`](/api/isOfType.md)