Customizing Axes Test
This bar chart displays the populations of the top 10 most populous countries in 2018, based on data from the United Nations World Population Prospects. It emphasizes customizing D3 axes: the x-axis uses tick formatting to abbreviate numbers (e.g., “B” for billions), while grid lines extend across the plot via `tickSize`. The y-axis labels remain unformatted. Built with D3 v5, the SVG chart uses `scaleLinear`, `scaleBand`, `axisBottom`, and `axisLeft`, with custom text elements for the title and axis label. Population values are multiplied by 1000 in the code.