Select a single body element

bind 4, 8, 15, 16, 23, and 42 as an array to a variable named data

Append a div to an already selected body element

Store the newly appended div in a variable named div

Put "Hello, world!" as html to an already selected div element

Select all elements tagged as "section"

Store this in a variable named section

What element does "Hello, world!" end up getting added to?

d3.selectAll("section").attr("class", "special").append("div").html("Hello, world!");

Store the data join of bar and data into barUpdate

The bar selection is defined as bar
The data selection is defined as data