Flag w/ Array

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)
/*
     svg.append("rect")
      .attr("y",100)
      .attr("x", 200)
    	.attr("width", 50)
    	.attr("height",100)
    	.attr("fill", "blue");
    	
     svg.append("rect")
      .attr("y", 150)
      .attr("x", 250)
    	.attr("width", 50)
    	.attr("height",100)
    	.attr("fill", "white");
    
     svg.append("rect")
      .attr("y", 100)
      .attr("x", 300)
    	.attr("width", 50)
    	.attr("height",100)
    	.attr("fill", "red");
 */
  
  
    
    var flag = [{"fill":"blue", "x":100},
               {"fill": "white", "x": 300},
               {"fill":"red", "x":500}];
    
    console.log(flag);
    
    svg.selectAll("rect")
    .data(flag)
    .enter()
    .append("rect")
    .attr("y", 100)
    .attr("x", function(d) {return d.x;})
    .attr("width", 200)
    .attr("height", 400)
    .attr("fill", function(d) {return d.fill;});
  </script>
</body>

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