This example demonstrates core JavaScript array manipulation techniques using D3 v6’s ascending helper for sorting. The code defines a custom range function to generate numeric arrays, then explores iteration with forEach and for loops, filtering, sorting with custom comparators, mapping to transformed values, and reducing to cumulative sums. It also sorts an array of objects by a key property using d3.ascending, and includes commented examples of reduce-based object conversion. No visualization is rendered; the example focuses purely on console-based array operations.