--- id: 5d8a4cfbe6b6180ed9a1ca09 title: Part 44 challengeType: 0 --- ## Description
The line needs x and y values for each point of data. Chain `x` to the line and pass it a "d function". Here's how that will look: ```js .x(d => d.year) ``` You will be passing your `data` array to this line function, where it will go through each item in the array(`d`) and create an x value based on the year(`d.year`). This is the first place you have seen a "d function". These are common in D3 and that is how I will refer to them throughout this project.
## Instructions
## Tests
```yml tests: - text: test-text testString: assert(/const twitterLine = d3\.line\(\)\s*\.x\s*\(\s*d\s*=>\s*d\.year\s*\)/g.test(code)); ```
## Challenge Seed
```html ```
### Before Test
```html D3 Dashboard
```
## Solution
```html ```