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---
id: 587d7fa9367417b2b2512bcf
title: Dynamically Change the Height of Each Bar
challengeType: 6
forumTopicId: 301486
dashedName: dynamically-change-the-height-of-each-bar
---
# --description--
The height of each bar can be set to the value of the data point in the array, similar to how the `x` value was set dynamically.
```js
selection.attr("property", (d, i) => {
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})
```
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Here `d` would be the data point value, and `i` would be the index of the data point in the array.
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# --instructions--
Change the callback function for the `height` attribute to return the data value times 3.
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**Note:** Remember that multiplying all data points by the same constant scales the data (like zooming in). It helps to see the differences between bar values in this example.
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# --hints--
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The first `rect` should have a `height` of `36` .
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```js
assert($('rect').eq(0).attr('height') == '36');
```
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The second `rect` should have a `height` of `93` .
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```js
assert($('rect').eq(1).attr('height') == '93');
```
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The third `rect` should have a `height` of `66` .
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```js
assert($('rect').eq(2).attr('height') == '66');
```
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The fourth `rect` should have a `height` of `51` .
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```js
assert($('rect').eq(3).attr('height') == '51');
```
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The fifth `rect` should have a `height` of `75` .
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```js
assert($('rect').eq(4).attr('height') == '75');
```
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The sixth `rect` should have a `height` of `54` .
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```js
assert($('rect').eq(5).attr('height') == '54');
```
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The seventh `rect` should have a `height` of `87` .
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```js
assert($('rect').eq(6).attr('height') == '87');
```
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The eighth `rect` should have a `height` of `42` .
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```js
assert($('rect').eq(7).attr('height') == '42');
```
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The ninth `rect` should have a `height` of `27` .
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```js
assert($('rect').eq(8).attr('height') == '27');
```
# --seed--
## --seed-contents--
```html
< body >
< script >
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
const w = 500;
const h = 100;
const svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h);
svg.selectAll("rect")
.data(dataset)
.enter()
.append("rect")
.attr("x", (d, i) => i * 30)
.attr("y", 0)
.attr("width", 25)
.attr("height", (d, i) => {
// Add your code below this line
// Add your code above this line
});
< / script >
< / body >
```
# --solutions--
```html
< body >
< script >
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
const w = 500;
const h = 100;
const svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h);
svg.selectAll("rect")
.data(dataset)
.enter()
.append("rect")
.attr("x", (d, i) => i * 30)
.attr("y", 0)
.attr("width", 25)
.attr("height", (d, i) => {
return d * 3
});
< / script >
< / body >
```
