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---
id: 587d7fa8367417b2b2512bc9
title: Update the Height of an Element Dynamically
challengeType: 6
---
## Description
< section id = 'description' >
The previous challenges covered how to display data from an array and how to add CSS classes. You can combine these lessons to create a simple bar chart. There are two steps to this:
1) Create a < code > div< / code > for each data point in the array
2) Give each < code > div< / code > a dynamic height, using a callback function in the < code > style()< / code > method that sets height equal to the data value
Recall the format to set a style using a callback function:
< code > selection.style("cssProperty", (d) => d)< / code >
< / section >
## Instructions
< section id = 'instructions' >
Add the < code > style()< / code > method to the code in the editor to set the < code > height< / code > property for each element. Use a callback function to return the value of the data point with the string "px" added to it.
< / section >
## Tests
< section id = 'tests' >
```yml
tests:
- text: The first < code > div</ code > should have a < code > height</ code > of 12 pixels.
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testString: assert($('div').eq(0).css('height') == '12px', 'The first < code > div< / code > should have a < code > height< / code > of 12 pixels.');
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- text: The second < code > div</ code > should have a < code > height</ code > of 31 pixels.
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testString: assert($('div').eq(1).css('height') == '31px', 'The second < code > div< / code > should have a < code > height< / code > of 31 pixels.');
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- text: The third < code > div</ code > should have a < code > height</ code > of 22 pixels.
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testString: assert($('div').eq(2).css('height') == '22px', 'The third < code > div< / code > should have a < code > height< / code > of 22 pixels.');
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- text: The fourth < code > div</ code > should have a < code > height</ code > of 17 pixels.
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testString: assert($('div').eq(3).css('height') == '17px', 'The fourth < code > div< / code > should have a < code > height< / code > of 17 pixels.');
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- text: The fifth < code > div</ code > should have a < code > height</ code > of 25 pixels.
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testString: assert($('div').eq(4).css('height') == '25px', 'The fifth < code > div< / code > should have a < code > height< / code > of 25 pixels.');
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- text: The sixth < code > div</ code > should have a < code > height</ code > of 18 pixels.
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testString: assert($('div').eq(5).css('height') == '18px', 'The sixth < code > div< / code > should have a < code > height< / code > of 18 pixels.');
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- text: The seventh < code > div</ code > should have a < code > height</ code > of 29 pixels.
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testString: assert($('div').eq(6).css('height') == '29px', 'The seventh < code > div< / code > should have a < code > height< / code > of 29 pixels.');
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- text: The eighth < code > div</ code > should have a < code > height</ code > of 14 pixels.
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testString: assert($('div').eq(7).css('height') == '14px', 'The eighth < code > div< / code > should have a < code > height< / code > of 14 pixels.');
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- text: The ninth < code > div</ code > should have a < code > height</ code > of 9 pixels.
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testString: assert($('div').eq(8).css('height') == '9px', 'The ninth < code > div< / code > should have a < code > height< / code > of 9 pixels.');
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```
< / section >
## Challenge Seed
< section id = 'challengeSeed' >
< div id = 'html-seed' >
```html
< style >
.bar {
width: 25px;
height: 100px;
display: inline-block;
background-color: blue;
}
< / style >
< body >
< script >
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
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d3.select("body").selectAll("div")
.data(dataset)
.enter()
.append("div")
.attr("class", "bar")
// Add your code below this line
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// Add your code above this line
< / script >
< / body >
```
< / div >
< / section >
## Solution
< section id = 'solution' >
```js
// solution required
```
< / section >
