---
id: 5d8a4cfbe6b6180ed9a1ca52
title: Part 115
challengeType: 0
---

## Description
<section id='description'>

`append` a `tr` element to the selection and then append a `th` element right after it. `tr` is for defining a row of the table, and `th` is for defining the header cells of the table.
</section>

## Instructions
<section id='instructions'>
</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: test-text
    testString: assert($('.dashboard div table thead tr th').length === 1);

```

</section>

## Challenge Seed
<section id='challengeSeed'>
<div id='html-seed'>

```html
<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.twitter))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', twitterColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('tumblr-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.tumblr))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', tumblrColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('instagram-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.instagram))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', instagramColor)
    .style('cursor', 'pointer')

  const rightDashboard = d3.select('.dashboard')
    .append('div');

  const pieGraph = rightDashboard.append('svg')
    .attr('width', 200)
    .attr('height', 200)

  const pieArc = d3.arc()
    .outerRadius(100)
    .innerRadius(0);

  const pieColors = d3.scaleOrdinal()  
    .domain(data[8].followers)
    .range([twitterColor, tumblrColor, instagramColor]);

  const pie = d3.pie()
    .value(d => d.value);
    
  const pieGraphData = pieGraph.selectAll('pieSlices')
    .data(pie(d3.entries(data[8].followers)))
    .enter()
    .append('g')
    .attr('transform', 'translate(100, 100)');

  pieGraphData.append('path')
    .attr('d', pieArc)
    .attr('fill', d => pieColors(d.data.key))
    .attr('stroke', 'white')
    .attr('stroke-width', 2);

  pieGraphData.append('text')
    .text(d => {
      const values = d3.values(data[8].followers);
      const sum = d3.sum(values);
      const percent = d.data.value/sum;
      return `${ Math.round(percent*100) }%`;
    })
    .attr('transform', d => `translate(${pieArc.centroid(d)})`)
    .style('text-anchor', 'middle')
    .style('font', '10px verdana');

  const legend = rightDashboard.append('table')
    .attr('width', 200)
    .attr('height', 120)
    .style('font', '12px verdana')

  const legendTitle = legend.append('thead')



</script>
```

</div>


### Before Test
<div id='html-setup'>

```html
<!DOCTYPE html>
<html>
  <head>
    <title>D3 Dashboard</title>
    <style>
      body {
        background-color: #ccc;
        padding: 100px 10px;
      }

      .dashboard {
        width: 980px;
        height: 500px;
        background-color: white;
        box-shadow: 5px 5px 5px 5px #888;
        margin: auto;
        display: flex;
        align-items: center;
      }
    </style>
  </head>

  <body>
    <div class="dashboard"></div>
  </body>
</html>
```

</div>
</section>


## Solution
<section id='solution'>

```html
<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.twitter))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', twitterColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('tumblr-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.tumblr))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', tumblrColor)
    .style('cursor', 'pointer')

  lineGraph.selectAll('instagram-circles')
    .data(data)
    .enter()
    .append('circle')
    .attr('cx', d => xScale(d.year))
    .attr('cy', d => yScale(d.followers.instagram))
    .attr('r', 6)
    .attr('fill', 'white')
    .attr('stroke', instagramColor)
    .style('cursor', 'pointer')

  const rightDashboard = d3.select('.dashboard')
    .append('div');

  const pieGraph = rightDashboard.append('svg')
    .attr('width', 200)
    .attr('height', 200)

  const pieArc = d3.arc()
    .outerRadius(100)
    .innerRadius(0);

  const pieColors = d3.scaleOrdinal()  
    .domain(data[8].followers)
    .range([twitterColor, tumblrColor, instagramColor]);

  const pie = d3.pie()
    .value(d => d.value);
    
  const pieGraphData = pieGraph.selectAll('pieSlices')
    .data(pie(d3.entries(data[8].followers)))
    .enter()
    .append('g')
    .attr('transform', 'translate(100, 100)');

  pieGraphData.append('path')
    .attr('d', pieArc)
    .attr('fill', d => pieColors(d.data.key))
    .attr('stroke', 'white')
    .attr('stroke-width', 2);

  pieGraphData.append('text')
    .text(d => {
      const values = d3.values(data[8].followers);
      const sum = d3.sum(values);
      const percent = d.data.value/sum;
      return `${ Math.round(percent*100) }%`;
    })
    .attr('transform', d => `translate(${pieArc.centroid(d)})`)
    .style('text-anchor', 'middle')
    .style('font', '10px verdana');

  const legend = rightDashboard.append('table')
    .attr('width', 200)
    .attr('height', 120)
    .style('font', '12px verdana')

  const legendTitle = legend.append('thead')
    .append('tr')
    .append('th')



</script>
```

</section>