> ## 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.

# Logical Functions

> This article provides a detailed overview of all logical functions available on the YiDA platform, including EQ, NE, AND, OR, and more, with examples of how these functions are used in real scenarios. Understanding these functions helps you build and manage form logic more effectively.

The table below summarizes each logical function, along with issues you may encounter when using them.

### Function Overview

| **Function name**                            | **Description**                                                                                                    |
| -------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
| [EQ](/yida/form/xdtv56ngunnhppyw)            | Checks whether two values are equal.                                                                               |
| [NE](/yida/form/escqg551suxgr6gq)            | Checks whether two values are not equal.                                                                           |
| [AND](/yida/form/uobzicixvh02io31)           | Returns true when all specified conditions are met.                                                                |
| [OR](/yida/form/ig680t7ur2cl0y4d)            | Returns true when at least one of the specified conditions is met.                                                 |
| [NOT](/yida/form/rzixdcx24zsd1ldx)           | Reverses the logical value of its argument.                                                                        |
| [XOR](/yida/form/evp4gkq8kcv4hgga)           | Performs an exclusive OR operation (a specific logical check used in computer science).                            |
| [FALSE](/yida/form/lks3ggo5cktvq213)         | Returns the logical value false.                                                                                   |
| [TRUE](/yida/form/wn65drd666xdl3b1)          | Returns the logical value true.                                                                                    |
| [GE](/yida/form/pkiwut48qyfax6h5)            | Greater than or equal to.                                                                                          |
| [LE](/yida/form/nvnp2kkbb94y8u9e)            | Less than or equal to.                                                                                             |
| [GT](/yida/form/rcyqy4mriwgq5nc2)            | Greater than.                                                                                                      |
| [LT](/yida/form/hkv6w6z366q9mg7i)            | Less than.                                                                                                         |
| [IF](/yida/form/dzzlham7l7xfr6wo)            | Performs a conditional check.                                                                                      |
| [ISEMPTY](/yida/form/gf7g82pavtbc4y5g)       | Checks whether a field is empty.                                                                                   |
| [ISNULL](/yida/form/zia9xssidpga5tqx)        | Checks whether a component value in a details table is empty, or whether the value of a multi-select box is empty. |
| [HASEMPTYTEXT](/yida/form/klvwx6gxfw6g6fgs)  | Checks whether the array value submitted by a component in a details table contains an empty string.               |
| [TIMECOMPARE](/yida/form/orqe469rrf2yn6gr)   | Compares two times. Returns true if Date picker 1 is greater than Date picker 2; otherwise, returns false.         |
| [NUMBERCOMPARE](/yida/form/mu292cs9i21m82yh) | Compares two numbers. Returns true if Numerical component 1 > Numerical component 2; otherwise, returns false.     |

## Introduction to Functions

Logical functions are a category of functions that return either the logical value **true** or the logical value **false**.

* true: Indicates that the result of the check is true or correct. It can also be represented by 1.
* false: Indicates that the result of the check is false or incorrect. It can also be represented by 0.

## Common Scenarios

### Block Form Submission When a Formula Is Met

Block form submission when the product name equals "Watermelon". See the following example.

### Requisition Quantity Cannot Exceed Stock Quantity

In business scenarios such as inventory management systems and product stock management, you often need to ensure that the requisition quantity does not exceed the stock quantity. See the following example.

### Nested IF Functions

Below 60 is Fail; 60 to 89 is Average; 90 and above is Excellent. See the following example.