How to get data from nested json file for d3.js?

@jasen_gottlieb 

To get data from a nested JSON file for d3.js, you can follow these steps:

1. Read the JSON file: First, you need to read the JSON file using an AJAX request or any other method available in your programming language.
2. Parse the JSON data: Once you have read the JSON file, you need to parse the JSON data using a JSON parser function. Most programming languages provide built-in functions to parse JSON data.
3. Traverse the nested structure: In order to access the nested data in the JSON file, you need to traverse the nested structure using loops or recursive functions. Depending on the structure of your JSON file, you may need to use nested loops or recursive functions to access the required data.
4. Extract the required data: Once you have traversed the nested structure, you can extract the required data and store it in a format that can be easily used by d3.js. This could be an array of objects or any other data structure that d3.js can manipulate.
5. Use the data in d3.js: Finally, you can use the extracted data in d3.js to create visualizations such as charts, graphs, or maps. You can pass the data to d3.js functions like d3.select() and d3.data() to bind the data to HTML elements and create visualizations.

By following these steps, you can effectively extract and use nested data from a JSON file for d3.js visualizations.