---
id: 5d79253307ecd49e030bdcd1
title: Part 023
challengeType: 0
isBeta: true
---
## Description
Recursion is when a function calls itself. We often use it instead of `while`/`for` loops, as loops usually involve mutable state.
Replace the empty string in `highPrecedence` with a call to `highPrecedence` with `str2` as argument.
## Instructions
## Tests
```yml
tests:
- text: See description above for instructions.
testString: assert(highPrecedence("2*2*2") === "8" && highPrecedence("2*2") === "4" && highPrecedence("2+2") === "2+2");
```
## Challenge Seed
```html
```
### Before Test
### After Test
```html
```
## Solution