This example demonstrates how to build a simple smiley face using D3.js, with a yellow circle for the head, black circles for the eyes, and an arc for the mouth. The code uses D3’s `select` and `arc` APIs to create and position SVG elements, relying on the `attr` method to set coordinates and dimensions based on the SVG’s width and height. The face is rendered entirely in SVG, with no external data source, and serves as a basic introduction to DOM manipulation with D3.