--- id: 587d7fa7367417b2b2512bc7 title: Change Styles Based on Data challengeType: 6 forumTopicId: 301479 dashedName: change-styles-based-on-data --- # --description-- D3 is about visualization and presentation of data. It's likely you'll want to change the styling of elements based on the data. You can use a callback function in the `style()` method to change the styling for different elements. For example, you may want to color a data point blue if it has a value less than 20, and red otherwise. You can use a callback function in the `style()` method and include the conditional logic. The callback function uses the `d` parameter to represent the data point: ```js selection.style("color", (d) => { }); ``` The `style()` method is not limited to setting the `color` - it can be used with other CSS properties as well. # --instructions-- Add the `style()` method to the code in the editor to set the `color` of the `h2` elements conditionally. Write the callback function so if the data value is less than 20, it returns red, otherwise it returns green. **Note:** You can use if-else logic, or the ternary operator. # --hints-- The first `h2` should have a `color` of red. ```js assert($('h2').eq(0).css('color') == 'rgb(255, 0, 0)'); ``` The second `h2` should have a `color` of green. ```js assert($('h2').eq(1).css('color') == 'rgb(0, 128, 0)'); ``` The third `h2` should have a `color` of green. ```js assert($('h2').eq(2).css('color') == 'rgb(0, 128, 0)'); ``` The fourth `h2` should have a `color` of red. ```js assert($('h2').eq(3).css('color') == 'rgb(255, 0, 0)'); ``` The fifth `h2` should have a `color` of green. ```js assert($('h2').eq(4).css('color') == 'rgb(0, 128, 0)'); ``` The sixth `h2` should have a `color` of red. ```js assert($('h2').eq(5).css('color') == 'rgb(255, 0, 0)'); ``` The seventh `h2` should have a `color` of green. ```js assert($('h2').eq(6).css('color') == 'rgb(0, 128, 0)'); ``` The eighth `h2` should have a `color` of red. ```js assert($('h2').eq(7).css('color') == 'rgb(255, 0, 0)'); ``` The ninth `h2` should have a `color` of red. ```js assert($('h2').eq(8).css('color') == 'rgb(255, 0, 0)'); ``` # --seed-- ## --seed-contents-- ```html ``` # --solutions-- ```html ```