add second line to d3.js line chart example

how to add second line to d3.js simple line chart

by Dhanesh Mane

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.js"></script>
<p>lets add second line to our example</p>

CSS

.axis path {
			fill: none;
			stroke: #777;
			shape-rendering: crispEdges;
		}
		.axis text {
			font-family: Lato;
			font-size: 13px;
		}
		.axis line {
		  fill: none;
		  stroke: #000;
		  shape-rendering: crispEdges;
		}
		.grid path,
		.grid line {
		  fill: none;
		  stroke: rgba(0, 0, 0, 0.25);
		  shape-rendering: crispEdges;
		}
    .tick line{
    opacity: 0.2;
  }

JavaScript

// chart data
	var chartConfig = { data:[{ "sale": "190", "year": "2000" }, { "sale": "215", "year": "2001" }, { "sale": "179", "year": "2002" }, { "sale": "199", "year": "2003" }, { "sale": "134", "year": "2004" }, { "sale": "176", "year": "2010" }],
 data2:[{ "sale": "200", "year": "2000" }, { "sale": "180", "year": "2001" }, { "sale": "195", "year": "2002" }, { "sale": "200", "year": "2003" }, { "sale": "176", "year": "2004" }, { "sale": "196", "year": "2010" }] };
  
  	// enviornment setup
		var svgConfig = {
						id:"mySvg",
						width:600,
						height:300,
						margin : {
							top: 20,
							right: 20,
							bottom: 20,
							left: 50
						  }
						};
            
	// drawing
		// append svg element
			var bodySelection = d3.select("body");
			
			var svgSelection  = bodySelection.append("svg")
								.attr("id", svgConfig.id)
								.attr("width",svgConfig.width)
								.attr("height",svgConfig.height);
								
		// create x scale
			xScale = d3.scale.linear()
					   .range([svgConfig.margin.left, svgConfig.width - svgConfig.margin.right])
					   .domain([ d3.min(chartConfig.data, function(d) {return +d.year;}), d3.max(chartConfig.data, function(d) {return +d.year;}) ]);
		
		// create y scale
			yScale = d3.scale.linear()
					   .range([svgConfig.height - svgConfig.margin.top, svgConfig.margin.bottom])
					   .domain([ d3.min(chartConfig.data, function(d) {return +d.sale;}), d3.max(chartConfig.data, function(d) {return +d.sale;}) ]);
		
		//let's create the axes using the scales
			xAxis = d3.svg.axis()
					.scale(xScale)
					.tickFormat(d3.format("d"))
          .innerTickSize(-svgConfig.height);
			
			yAxis = d3.svg.axis()
					.orient("left")
					.scale(yScale)
          .innerTickSize(-svgConfig.width);
		
		// add xaxis to chart - it will add it to top of the svg
			svgSelection.append("svg:g")
			.attr("id","xAxis")
			.attr("class","axis")
			.call(xAxis);
			
		// The X axis is drawn but it has some issues. First, we need...