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---
id: 587d7fa8367417b2b2512bc9
title: Update the Height of an Element Dynamically
required:
- src: 'https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js'
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
- 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 >
