This example displays a list of the ten most populous countries by rendering each country’s name as a separate heading. The code uses D3 v4’s data join pattern—`d3.select("body").selectAll("h1").data(data).enter().append("h1")`—to bind an array of objects containing name and population values to new `h1` elements, with the text set to each datum’s `name` property. The data is hardcoded in the script, and the visualization demonstrates the basic structure of a D3-powered HTML page.