# Function

A function is a reusable block of code that performs a specific task. It's like a mini-program within your main program. You give it a name, define what it does, and then you can "call" or use it multiple times in your code without having to write the same instructions repeatedly.

![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXfPBNVlgrAw_l-a9k-uZwmJ7FizYabnP4fos811UUpGuTOGG0ZUoTxdB77o45qEMs2XJXwJMJozcJ2bLDN9i4YAtjSrmNRInoYCI9p9czKO3z-Cf84jtE1rVVWoPy7VU-Kxi3Ok5KWVppjaPkm3WnvkioIs?key=hRw9bBhBfp1lHBJ7rUAI2Q)

**to do something**

![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXfGJFB53z0ZBkvWpqbLdW9YkEVfjgZjgYHBYaCFRTRw8DK9XTFqqXcYdp0ZPWAbVwwn6pIHa0sex3IOHZuhsCH9K-Ywr36rrIHV1Qzmh70qmiRswuzJpV57g33rcDm4WNz08BddpCqkZXGN6xEaVf0kuwHz?key=hRw9bBhBfp1lHBJ7rUAI2Q)

Creates a function with no output.

Key points:

* You can change “do something” to a unique tag for your future reference.
* This function has no output.

**to do something return**

![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXd9-dAApbxlEsdJ_cjDcZQCpjd720NX5QDaRO49TT1POpqr4JNVANytYlh9kixCb0jsrd3AsJ7UdaeQweIDAA8lfKHZD9ylTIY_1hubbxd5KdqyBalM6LBRBCZPGPxGJyMfQ7Eg_T1yiUfav6lWCby7nw1j?key=hRw9bBhBfp1lHBJ7rUAI2Q)

Creates a function with an output.

Key points:

* You can change “do something” to a unique tag for your future reference.
* This function returns a value as specified.

**if return**

![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXc_eE5AllPcYagbl7LA-2LaHt_xbAXMeogTrA78a6JDYxaQHZVy4VLYkeWq1b_ERybipLryN6Vw7oEeeg2jYMSmZ8MbA6RG1Yk1hHgHnZFRUjqGaVdXah1TQgjtu-2NwXzu7faCW_qgv0YsyJhjbXuqx-4?key=hRw9bBhBfp1lHBJ7rUAI2Q)

If a value is true, then return the second value. 

Key points:

* This block can only be used within a function.
* When the condition is true and the value is returned, no other blocks will be executed anymore.

**runOpMode**

![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXfeBnXUomTDcUj2O1PBJLxVzfh3yPlQumjd6CGziOoQo8de4z9o_496ONmGtSJ8XS7Lp12d5TpohmRaAfn-GUMdlCHWmhd12EM80_5JO3I9XKRm_L2EEbprJm79DymnSZTEfv4U1k23OqXZJBSTAP8V2cY?key=hRw9bBhBfp1lHBJ7rUAI2Q)

Run the user defined function “runOpMode”. You may have defined a function with a different name. The user defined function name will auto populate in the functions list.


---

# Agent Instructions: 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:

```
GET https://vrs-guidebook-2nd-edition.gitbook.io/vrs-guidebook-2nd-edition/programming/blocks/function.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.