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challengeType

587d7fa8367417b2b2512bca

Change the Presentation of a Bar Chart

src
https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js

Description

The last challenge created a bar chart, but there are a couple of formatting changes that could improve it: 1) Add space between each bar to visually separate them, which is done by adding a margin to the CSS for the bar class 2) Increase the height of the bars to better show the difference in values, which is done by multiplying the value by a number to scale the height

Instructions

First, add a margin of 2px to the bar class in the style tag. Next, change the callback function in the style() method so it returns a value 10 times the original data value (plus the "px"). Note
Multiplying each data point by the same constant only alters the scale. It's like zooming in, and it doesn't change the meaning of the underlying data.

Tests

tests:
  - text: The first <code>div</code> should have a <code>height</code> of 120 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(0).css(''height'') == ''120px'' && $(''div'').eq(0).css(''margin-right'') == ''2px'', ''The first <code>div</code> should have a <code>height</code> of 120 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The second <code>div</code> should have a <code>height</code> of 310 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(1).css(''height'') == ''310px'' && $(''div'').eq(1).css(''margin-right'') == ''2px'', ''The second <code>div</code> should have a <code>height</code> of 310 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The third <code>div</code> should have a <code>height</code> of 220 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(2).css(''height'') == ''220px'' && $(''div'').eq(2).css(''margin-right'') == ''2px'', ''The third <code>div</code> should have a <code>height</code> of 220 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The fourth <code>div</code> should have a <code>height</code> of 170 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(3).css(''height'') == ''170px'' && $(''div'').eq(3).css(''margin-right'') == ''2px'', ''The fourth <code>div</code> should have a <code>height</code> of 170 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The fifth <code>div</code> should have a <code>height</code> of 250 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(4).css(''height'') == ''250px'' && $(''div'').eq(4).css(''margin-right'') == ''2px'', ''The fifth <code>div</code> should have a <code>height</code> of 250 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The sixth <code>div</code> should have a <code>height</code> of 180 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(5).css(''height'') == ''180px'' && $(''div'').eq(5).css(''margin-right'') == ''2px'', ''The sixth <code>div</code> should have a <code>height</code> of 180 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The seventh <code>div</code> should have a <code>height</code> of 290 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(6).css(''height'') == ''290px'' && $(''div'').eq(6).css(''margin-right'') == ''2px'', ''The seventh <code>div</code> should have a <code>height</code> of 290 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The eighth <code>div</code> should have a <code>height</code> of 140 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(7).css(''height'') == ''140px'' && $(''div'').eq(7).css(''margin-right'') == ''2px'', ''The eighth <code>div</code> should have a <code>height</code> of 140 pixels and a <code>margin</code> of 2 pixels.'');'
  - text: The ninth <code>div</code> should have a <code>height</code> of 90 pixels and a <code>margin</code> of 2 pixels.
    testString: 'assert($(''div'').eq(8).css(''height'') == ''90px'' && $(''div'').eq(8).css(''margin-right'') == ''2px'', ''The ninth <code>div</code> should have a <code>height</code> of 90 pixels and a <code>margin</code> of 2 pixels.'');'

Challenge Seed

<style>
  .bar {
    width: 25px;
    height: 100px;
    /* Add your code below this line */
    
    /* Add your code above this line */
    display: inline-block;
    background-color: blue;
  }
</style>
<body>
  <script>
    const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
    
    d3.select("body").selectAll("div")
      .data(dataset)
      .enter()
      .append("div")
      .attr("class", "bar")
      // Add your code below this line
      .style("height", (d) => (d + "px"))
      
      // Add your code above this line
  </script>
</body>

Solution

// solution required

5.1 KiB Raw Blame History