96 lines
3.8 KiB
Markdown
96 lines
3.8 KiB
Markdown
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---
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id: 587d7fa8367417b2b2512bc9
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title: Update the Height of an Element Dynamically
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required:
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- src: 'https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js'
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challengeType: 6
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---
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## Description
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<section id='description'>
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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:
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1) Create a <code>div</code> for each data point in the array
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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
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Recall the format to set a style using a callback function:
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<code>selection.style("cssProperty", (d) => d)</code>
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</section>
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## Instructions
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<section id='instructions'>
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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.
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- 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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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='html-seed'>
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```html
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<style>
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.bar {
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width: 25px;
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height: 100px;
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display: inline-block;
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background-color: blue;
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}
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</style>
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<body>
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<script>
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const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
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d3.select("body").selectAll("div")
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.data(dataset)
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.enter()
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.append("div")
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.attr("class", "bar")
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// Add your code below this line
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// Add your code above this line
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</script>
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</body>
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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