93 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			93 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
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								---
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								id: 587d7fa9367417b2b2512bcf
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								title: Dynamically Change the Height of Each Bar
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								challengeType: 6
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								videoUrl: ''
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								localeTitle: 动态改变每个栏的高度
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								---
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								## Description
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								<section id="description">每个条的高度可以设置为数组中数据点的值,类似于动态设置<code>x</code>值的方式。 <blockquote> selection.attr(“property”,(d,i)=> { <br> / * <br> * d是数据点值<br> * i是数组中数据点的索引<br> * / <br> }) </blockquote></section>
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								## Instructions
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								<section id="instructions">更改<code>height</code>属性的回调函数以返回数据值乘以3. <strong>注意</strong> <br>请记住,将所有数据点乘以相同的常量可以缩放数据(如放大)。在此示例中,有助于查看条形值之间的差异。 </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: 第一个<code>rect</code>的<code>height</code>应为36。
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								    testString: 'assert($("rect").eq(0).attr("height") == "36", "The first <code>rect</code> should have a <code>height</code> of 36.");'
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								  - text: 第二个<code>rect</code>的<code>height</code>应为93。
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								    testString: 'assert($("rect").eq(1).attr("height") == "93", "The second <code>rect</code> should have a <code>height</code> of 93.");'
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								  - text: 第三个<code>rect</code>的<code>height</code>应为66。
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								    testString: 'assert($("rect").eq(2).attr("height") == "66", "The third <code>rect</code> should have a <code>height</code> of 66.");'
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								  - text: 第四个<code>rect</code>的<code>height</code>应为51。
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								    testString: 'assert($("rect").eq(3).attr("height") == "51", "The fourth <code>rect</code> should have a <code>height</code> of 51.");'
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								  - text: 第五个<code>rect</code>的<code>height</code>应为75。
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								    testString: 'assert($("rect").eq(4).attr("height") == "75", "The fifth <code>rect</code> should have a <code>height</code> of 75.");'
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								  - text: 第六个<code>rect</code>的<code>height</code>应为54。
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								    testString: 'assert($("rect").eq(5).attr("height") == "54", "The sixth <code>rect</code> should have a <code>height</code> of 54.");'
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								  - text: 第七个<code>rect</code>的<code>height</code>应为87。
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								    testString: 'assert($("rect").eq(6).attr("height") == "87", "The seventh <code>rect</code> should have a <code>height</code> of 87.");'
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								  - text: 第八个<code>rect</code>应该有42的<code>height</code> 。
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								    testString: 'assert($("rect").eq(7).attr("height") == "42", "The eighth <code>rect</code> should have a <code>height</code> of 42.");'
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								  - text: 第九个<code>rect</code>的<code>height</code>应为27。
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								    testString: 'assert($("rect").eq(8).attr("height") == "27", "The ninth <code>rect</code> should have a <code>height</code> of 27.");'
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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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								<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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								    const w = 500;
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								    const h = 100;
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								    const svg = d3.select("body")
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								                  .append("svg")
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								                  .attr("width", w)
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								                  .attr("height", h);
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								    svg.selectAll("rect")
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								       .data(dataset)
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								       .enter()
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								       .append("rect")
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								       .attr("x", (d, i) => i * 30)
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								       .attr("y", 0)
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								       .attr("width", 25)
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								       .attr("height", (d, i) => {
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								         // Add your code below this line
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								         // Add your code above this line
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								       });
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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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