simple bar chart with interaction

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    rect {
      fill: white;
      stroke: black;
      stroke-width: 1px;
    }
    
    path {
      fill: none;
      stroke: black;
    }
  </style>
</head>

var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500);

g.selectAll("rect").data(data).enter().append("rect")
    	.attr("x", function(d, i) { return x(i); })
    	.attr("y", function(d) { return 170 - y(d); })
    	.attr("height", function(d) { return y(d); })
			.attr("width", 500 / data.length - 10 )
    	.on("mouseover", function(d, i) {
      	d3.select(this).style("fill", "red");
				console.log(d3.select(this))
        
        
        // Using Ids instead of values
      	d3.selectAll("text").filter(function(e, j) {
          return i === j;
        })
        .style("font-size", 24);
      
    	})
    	.on("mouseout", function(d, i) {
      	d3.select(this).transition().duration(500).style("fill", "white");
        
        // Should be using Ids instead of values
      	d3.selectAll("text").filter(function(e, j) {
          return i === j;
        })
        .transition().duration(500)
        .style("font-size", 12);
      
    	});
    
    	var line = d3.line()
      	.curve(d3.curveCardinal)
      	.x(function(d, i) { return x(i) + 20; })
      	.y(function(d, i) { return 170 - y(d); })
    	
    	g.selectAll("path").data([data]).enter()
      	.append("path")
      	.attr("d", line)

</script>
</body>

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