4.2 bar chart | hover

<!DOCTYPE html>
<meta charset="utf-8">
<html>
<head>

<link href="https://fonts.googleapis.com/css2?family=Montserrat+Alternates:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Montserrat:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&family=Roboto:ital,wght@0,100;0,300;1,100;1,300&display=swap" rel="stylesheet">

<script src="https://d3js.org/d3.v4.min.js" charset="utf-8"></script>

<style>

/*Defining text stylings*/

#h1 {
  font-size:30px;
  margin:30px 0px 0px 20px;
  color:#f5fa91;
  font-family:'Montserrat Alternates', sans-serif;
  font-weight:300;
}

#link {
	font-family:'Montserrat Alternates', sans-serif;
  font-weight:200;
  font-size:10px;
	margin:5px 0px 0px 22px;
  color:white;
}

a:link, a:visited, a:active {
	text-decoration: none;
  color:white;
  border-bottom:1.5px dotted white;
}

body {
  background-color:#011227;
}

/*Defining chart stylings*/

.bar {
  fill:#85f6fa;
  fill-opacity:1;
}

.bar:hover {
  fill:WHITE;
  fill-opacity:1;
}

/*Defining axis stylings*/

.y-axis text, .x-axis text {
  font-family:'Montserrat Alternates', sans-serif;
  font-weight:400;
  font-size:9px;
  opacity:1;
  fill:white;
}

.y-axis path {
  fill:none;
  stroke-width:0;
  stroke-opacity:1;
  stroke:white;
}

.x-axis path {
  fill:none;
  stroke-width:0;
  stroke-opacity:1;
  stroke:white;
}

.y-axis line {
  fill:none;
  stroke-width:0.5;
  stroke-opacity:1;
  stroke:white;
  stroke-dasharray:2;
}

.x-axis line {
  fill:none;
  stroke-width:0;
  stroke-opacity:1;
  stroke:white;
  stroke-dasharray:2;
}

</style>
</head>

<body>
  

<p id="h1">BAR CHART | HOVER</p>
<div id="link">by
<a href="https://slides.com/sandravizmad">SANDRA</a></div>  
  
<script>

//Margin conventions
var m = {top:100, right:0, bottom:50, left:20}
    w = 950 - m.left - m.right,
    h = 650 - m.top - m.bottom;

//Container
var svg = d3.select("body")
    .append("svg")
    .attr("width", w + m.left + m.right)
    .attr("height", h + m.top + m.bottom)
    .append("g")
		.attr("transform", `translate(${m.left}, ${m.top})`);

//Data loading
d3.csv(
  "https://gist.githubusercontent.com/sandravizz/ad6c57187890d2356e487340043cf031/raw/6365b3f31e1f1a73bc3bc67740a110f268839c8a/OECD%2520Income%2520Inequality%2520by%2520country%25202015",
  prepare,
  data => {

//Sort data by value
  data.sort((b, a) => {return a.Value - b.Value;});

//X scale
  var x = d3.scaleBand()
    	.domain(data.map(d => d.LOCATION))
    	.rangeRound([0, w])
    	.paddingInner(0.03);

//Y scale
  var y = d3.scaleLinear()
      .domain([0, d3.max(data, d => d.Value)])
    	.range([h, 0]);

//X axis
  svg.append("g")
      .attr("class", "x-axis")
      .attr("transform", `translate(0, ${h})`)
      .call(d3.axisBottom(x));

//Y axis
  svg.append("g")
      .attr("class", "y-axis")
      .call(d3.axisLeft(y)
               .tickPadding(0)
               .tickValues([0.3, 0.4, 0.5, 0.6])
               .tickSize(-w)
               .ticks(4));

//Drawing the bars
  svg.selectAll(".bar")
      .data(data)
      .enter()
      .append("rect")
      .attr("class", "bar")
      .attr("x", d => x(d.LOCATION))
      .attr("width", x.bandwidth())
      .attr("y", d => y(d.Value))
    	.attr("height", d => h - y(d.Value));
});

//Make sure all variables are numbers
function prepare (d) {
  d.Value = +d.Value;
  return d;
}

</script>
</body>
</html>

https://d3js.org/d3.v4.min.js