This example demonstrates loading multiple JSON data files concurrently using D3 v5. It shows how to fetch three separate datasets and combine their results into a single array for further processing. The code uses `d3.json()` to request each file and `Promise.all()` to wait for all requests to complete before logging the combined values to the browser console. The visualization itself is not rendered—instead, the example focuses on the data-loading pattern, with the three JSON files containing simple objects with `foo` and `bar` properties. The approach highlights asynchronous data handling in D3 without any chart or graphical output.