> For the complete documentation index, see [llms.txt](https://vue-generators.gitbook.io/vue-generators/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vue-generators.gitbook.io/vue-generators/develop/validation/built-in-validators.md).

# Built in Validators

Built in validators are implemented [here](https://github.com/vue-generators/vue-form-generator/blob/master/src/utils/validators.js). Here is a list of the validators and what they do:

## number

Checks that the value is numeric - and that it's within the fields `min` & `max` range, if these are defined in the schema.

## integer

Checks that the value is a valid Javascript `Number` - and that it's an integer.

## double

Checks that the value is a valid number.

## string

Checks that the value is a string - and that its length is within the fields `min` & `max` range, if these are defined in the schema.

## array

Checks that the value is an array - and that the arrays `length` is within the fields `min` & `max` range, if these are defined in the schema.

Expects the value to be a valid Javascript array literal - something like this: `["John", "Doe", "Jane"]` or `[1, 2, 3]`.

## date

Checks that the value is a valid Javascript `Date` - and that the date is between the fields `min` and `max` dates, if these are defined in the schema.

## regexp

Checks that the value matches the regex defined in the fields `schema.pattern`. If `schema.pattern` isn't set, validation is skipped.

## email

Checks that the value is a plausible looking email address, using a regular expression.

## url

Checks that the value is a plausible looking http url, using a regular expression. Among other checks, the URL needs to start with `http://` or `https://`.

## creditCard

Checks that the value is a valid credit card number, using code from [here](https://github.com/chriso/validator.js).

## alpha

Checks that the value is a letter, using this regex: `/^[a-zA-Z]*$/`

## alphaNumeric

Checks that the value is a letter or a number, using this regex: `/^[a-zA-Z0-9]*$/`


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://vue-generators.gitbook.io/vue-generators/develop/validation/built-in-validators.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.