Javascript/TypeScript: How to Group Ratings by Date into Arrays

Learn how to effectively organize your data in `JavaScript` and `TypeScript` by grouping ratings based on their associated dates. This guide will show you how to convert complex objects into a structured format with clear examples.
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How to Group Ratings by Date into Arrays in JavaScript/TypeScript

In our daily programming tasks, we often need to manipulate data stored in various formats. One common requirement is to extract specific values from an object and restructure them in a more useful format. In this guide, we will explore how to take a complex object with nested arrays and convert it into a simpler format where we group values (ratings in this case) based on date.

The Problem at Hand

Suppose you have an array of objects representing questionnaire responses, where each object contains a date and a list of responses:

[[See Video to Reveal this Text or Code Snippet]]

Your goal is to transform this data into a new structure like the following:

[[See Video to Reveal this Text or Code Snippet]]

This new format consolidates ratings under each unique date.

The Solution Approach

Step 1: Use Array reduce to Group Data

The first step is to iterate over the original array and create a dictionary object. The reduce method is perfect for this, as it allows us to accumulate results across iterations.

Initialize the accumulator to collect the ratings by date.

Extract the relevant data from each object (the date and ratings).

Push ratings to their corresponding date entry in the accumulator.

Step 2: Convert the Dictionary into an Array

Sample Code Implementation

Here is how you can implement the above steps in JavaScript:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

The final map creates the structured output containing dates and their corresponding ratings as arrays.

Conclusion

By leveraging the power of reduce and map, you can effectively regroup and restructure complex data in JavaScript and TypeScript. This approach can easily be applied to various scenarios where data organization is key. With this method, you can streamline the process of data manipulation, making your code cleaner and more efficient.

Feel free to explore this solution in your own projects, and watch how much easier it becomes to handle and analyze your data!