> ## Documentation Index
> Fetch the complete documentation index at: https://help.dingtalk.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Validation Functions

> This article lists all validation functions provided by the YiDA platform, including ARRAYREPEATED, EXIST, and EXACT, to help you better understand and use these features.

The table below summarizes each validation function and links to its detailed usage and examples.

## Function Overview

| **Function name**                    | **Description**                                          |
| ------------------------------------ | -------------------------------------------------------- |
| [ARRAYREPEATED](/yida/form/fs8ym2)   | Checks whether an array contains duplicate values.       |
| [EXIST](/yida/form/vs0ddo8m5ggofmtb) | Checks whether a value exists in a given set.            |
| [EXACT](/yida/form/onabfl769bhounig) | Compares two strings for an exact, case-sensitive match. |