react components & es6
This example shows a simple smiley face rendered as an SVG, built with React components and ES6 syntax. The face consists of a yellow circle, two dark eye circles, and a mouth arc, all sized and positioned relative to the window dimensions. React 16.9 manages the component structure, while d3.v7 provides the `arc` generator to create the mouth’s path. The SVG is drawn with fixed pixel width and height, centered on the page, and uses stroke and fill attributes for styling.