.enter()

xxxxxxxxxx
 
<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v5.min.js"></script>
</head>
​
<body>
  <div class="chart"></div>
  
  <script>
    const svg = d3.select(".chart")
      .append("svg")
        .attr("width", 100)
        .attr("height", 600)
    
    svg.selectAll("rect")
        .data([10, 20, 30, 40])
        .enter()
      .append("rect")
        .attr("width", d => d)
        .attr("height", 40)
        .attr("x", 25)
        .attr("y", (d, i) => i * 50)
        .attr("fill", "red")
  </script>
</body>
    

https://d3js.org/d3.v5.min.js