---
id: 5d7925357a0533eb221b005d
title: Part 044
challengeType: 0
isBeta: true
---
## Description
Replace the call to `arr` in `arr.concat([end])` with `[start]` and remove the `arr` variable and its definition.
## Instructions
## Tests
```yml
tests:
- text: See description above for instructions.
testString: assert(!(code.includes("arr")) && code.replace(/\s/g, "").includes("[start].concat([end])"));
```
## Challenge Seed
```html
```
### Before Test
### After Test
```html
```
## Solution