freeCodeCamp/curriculum/challenges/english/04-data-visualization/data-visualization-with-d3/add-classes-with-d3.english.md

2.4 KiB

id title required challengeType
587d7fa7367417b2b2512bc8 Add Classes with D3
src
https://cdnjs.cloudflare.com/ajax/libs/d3/4.3.0/d3.min.js
6

Description

Using a lot of inline styles on HTML elements gets hard to manage, even for smaller apps. It's easier to add a class to elements and style that class one time using CSS rules. D3 has the attr() method to add any HTML attribute to an element, including a class name. The attr() method works the same way that style() does. It takes comma-separated values, and can use a callback function. Here's an example to add a class of "container" to a selection: selection.attr("class", "container");

Note that the "class" parameter will remain the same whenever you need to add a class and only the "container" parameter will change.

Instructions

Add the attr() method to the code in the editor and put a class of bar on the div elements.

Tests

tests:
  - text: Your <code>div</code> elements should have a class of <code>bar</code>.
    testString: assert($('div').attr('class') == "bar", 'Your <code>div</code> elements should have a class of <code>bar</code>.');
  - text: Your code should use the <code>attr()</code> method.
    testString: assert(code.match(/\.attr/g), 'Your code should use the <code>attr()</code> method.');

Challenge Seed

<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];

    d3.select("body").selectAll("div")
      .data(dataset)
      .enter()
      .append("div")
      // Add your code below this line



      // Add your code above this line
  </script>
</body>

Solution

<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];

    d3.select("body").selectAll("div")
      .data(dataset)
      .enter()
      .append("div")
      // Add your code below this line
      .attr("class","bar");
      // Add your code above this line
  </script>
</body>