> For the complete documentation index, see [llms.txt](https://calnix.gitbook.io/aave-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://calnix.gitbook.io/aave-book/functions/borrow/setborrowing.md).

# setBorrowing

## Overview

<figure><img src="https://1829638638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0k7YXwFGMFZcsyqkM4q1%2Fuploads%2FYLfyJEi2Nv99n8CBOZwd%2Fimage.png?alt=media&amp;token=9b5204d3-c965-4245-9cc5-f00f42155f62" alt=""><figcaption></figcaption></figure>

* [x] <mark style="color:orange;">cache</mark>
* [x] <mark style="color:orange;">updateState</mark>
* [x] getIsolationMode
* [x] validateBorrow
* [x] mint debt token
* [ ] setBorrowing&#x20;
* [ ] update IsolationMode debt
* [ ] <mark style="color:orange;">updateInterestRates</mark>
* [ ] transfer underlying to user

<img src="https://1829638638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0k7YXwFGMFZcsyqkM4q1%2Fuploads%2FBju20y8d9Wucd4OGSlUq%2Ffile.excalidraw.svg?alt=media&amp;token=1a9297d2-2882-4124-86e1-f6a10d62a404" alt="" class="gitbook-drawing">

**`bool ifFirstBorrowing`** captures the return value from either of the debt token's mint function. It is `true`, if the user had no debt previously, thereby making this incoming borrow action the user's very first one.

## setBorrowing

The function performs bitwise operations to set or unset the borrowing status for the specified reserve.

<figure><img src="https://1829638638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0k7YXwFGMFZcsyqkM4q1%2Fuploads%2FwxGeTETxJcsInWSdrCqI%2Fimage.png?alt=media&amp;token=47cbd1be-905e-47ad-b241-e2f19e93cb10" alt=""><figcaption></figcaption></figure>

It calculates the bit position based on the `reserveIndex` and creates a bit mask by left shifting `1` by twice the `reserveIndex` value. This mask is captured by the bit variable.

**Setting Borrowing Status:** If `borrowing` is true, the function uses a bitwise OR operation (`|=`) to set the corresponding bit in the `self.data` bitmap. This indicates that the user is borrowing the specified reserve.

**Unsetting Borrowing Status:** If borrowing is false, the function uses a bitwise AND operation (`&=`) with the bitwise negation (`~bit`) to unset the corresponding bit in the `self.data` map. This indicates that the user is not borrowing the specified reserve.

{% hint style="info" %}
For in-depth illustration on how this function works, see: [setUsingAsCollateral](/aave-book/functions/supply/isfirstsupply.md#setusingascollateral).

The process for both are similar, one sets the borrow flag, the other sets the collateral flag.
{% endhint %}