Enter the Data

Enter Selections

What if you don't know how much data you have?

An enter selection is the set of data elements that do not have an associated html element

var info = [57, 239, 2];
var container = d3.select("svg");
circles = container.selectAll("circle").data(info).enter();

circles is now an array of 3 objects with associated adata

circles.append("circle")

circles.append("circle").attr("cy", 250).attr("r", 40).attr("cx", function(d) {
  return d;
});