This example shows how to sort grouped bar charts in two distinct ways: either the bars within each group can be sorted by value, or the groups themselves can be sorted alphabetically. The visualization uses D3.js version 3 to render an SVG with an ordinal x-scale for states and an inner ordinal scale for age categories, with a linear y-scale for population counts. The code loads data from a CSV file containing state population figures across age brackets, and it adjusts the domain of the x0 scale to sort states alphabetically, while the A1–A3 comments enable sorting individual bars within each state by their values.