This example demonstrates how D3’s data join handles changing datasets, showing circles rendered from an array of five random integers. After drawing all circles, the code trims the data to three items, and the exit selection removes the extra circles from the SVG. It uses React 16.13 and D3 v6, with the `d3.randomInt` generator supplying values and D3’s selection methods (`data`, `enter`, `exit`) managing circle updates. The SVG is appended directly to the body, with no interactive behavior beyond the static removal.