langflow/docs/versioned_docs/version-1.8.0/Components/if-else.mdx

---
title: If-Else
slug: /if-else
---

import Icon from "@site/src/components/icon";
import PartialParams from '@site/docs/_partial-hidden-params.mdx';

The **If-Else** component is a conditional router that routes messages by comparing two strings.
It evaluates a condition by comparing two text inputs using the specified operator, and then routes the message to `true_result` or `false_result` depending on the evaluation.

The operator looks for single strings in the input (`input_text`) based on an operator and match text (`match_text`), but it can also search for multiple words by matching a regex.
Available operators include:

- **equals**: Exact match comparison
- **not equals**: Inverse of exact match
- **contains**: Checks if the `match_text` is found within `input_text`
- **starts with**: Checks if `input_text` begins with `match_text`
- **ends with**: Checks if `input_text` ends with `match_text`
- **regex**: Matches on a case-sensitive pattern

By default, all operators are case insensitive except **regex**.
**regex** is always case sensitive, and you can enable case sensitivity for all other operators in the [If-Else parameters](#if-else-parameters).

## Use the If-Else component in a flow

The following example uses the **If-Else** component to check incoming chat messages with regex matching, and then output a different response depending on whether the match evaluated to true or false.

![A conditional router connected to two OpenAI components](/img/component-conditional-router.png)

1. Add an **If-Else** component to your flow, and then configure it as follows:

    * **Text Input**: Connect the **Text Input** port to a **Chat Input** component or another `Message` input.

        If your input isn't in `Message` format, you can use another component to transform it, such as the [**Type Convert** component](/type-convert) or [**Parser** component](/parser).
        If your input isn't appropriate for `Message` format, consider using another component for conditional routing, such as the [**Data Operations** component](/data-operations).

    * **Match Text**: Enter `.*(urgent|warning|caution).*` so the component looks for these values in incoming input. The regex match is case sensitive, so if you need to look for all permutations of `warning`, enter `warning|Warning|WARNING`.

    * **Operator**: Select **regex**.

    * **Case True**: In the [component inspection panel](/concepts-components#component-menus), enable the **Case True** parameter, click **Close**, and then enter `New Message Detected` in the field.

        The **Case True** message is sent from the **True** output port when the match condition evaluates to true.

        No message is set for **Case False** so the component doesn't emit a message when the condition evaluates to false.

3. Depending on what you want to happen when the outcome is **True**, add components to your flow to execute that logic:

    1. Add a **Language Model**, **Prompt Template**, and **Chat Output** component to your flow.

    2. In the **Language Model** component, enter your OpenAI API key or select a different provider and model.

    3. Connect the **If-Else** component's **True** output port to the **Language Model** component's **Input** port.

    4. In the **Prompt Template** component, enter instructions for the model when the evaluation is true, such as `Send a message that a new warning, caution, or urgent message was received`.

    5. Connect the **Prompt Template** component to the **Language Model** component's **System Message** port.

    6. Connect the **Language Model** component's output to the **Chat Output** component.

4. Repeat the same process with another set of **Language Model**, **Prompt Template**, and **Chat Output** components for the **False** outcome.

    Connect the **If-Else** component's **False** output port to the second **Language Model** component's **Input** port.
    In the second **Prompt Template**, enter instructions for the model when the evaluation is false, such as `Send a message that a new low-priority message was received`.

5. To test the flow, open the **Playground**, and then send the flow some messages with and without your regex strings.
The chat output should reflect the instructions in your prompts based on the regex evaluation.

    ```text
    User: A new user was created.

    AI: A new low-priority message was received.

    User: Sign-in warning: new user locked out.

    AI: A new warning, caution, or urgent message was received. Please review it at your earliest convenience.
    ```

## If-Else parameters

<PartialParams />

| Name           | Type     | Description                                                       |
|----------------|----------|-------------------------------------------------------------------|
| input_text     | String   | Input parameter. The primary text input for the operation. |
| match_text     | String   | Input parameter. The text to compare against. |
| operator       | Dropdown | Input parameter. The operator used to compare texts. Options include `equals`, `not equals`, `contains`, `starts with`, `ends with`, and `regex`. The default is `equals`. |
| case_sensitive | Boolean  | Input parameter. When `true`, the comparison is case sensitive. The default is `false`. This setting doesn't apply to regex comparisons. |
| max_iterations | Integer  | Input parameter. The maximum number of iterations allowed for the conditional router. The default is 10. |
| default_route  | Dropdown | Input parameter. The route to take when max iterations are reached. Options include `true_result` or `false_result`. The default is `false_result`. |
| true_result  | Message | Output parameter. The output produced when the condition is true. |
| false_result | Message | Output parameter. The output produced when the condition is false. |