JavaScript Group By from Object

When working with JavaScript, you may often find the need to group objects based on a certain property. This can be particularly useful when dealing with large datasets or when you need to organize data for display purposes.

Thankfully, JavaScript provides a straightforward way to achieve this using the reduce method. In this article, we will explore how to use the reduce method to group objects from an array based on a specific property.

Example:

      
        const data = [
          { id: 1, name: 'Alice', group: 'A' },
          { id: 2, name: 'Bob', group: 'B' },
          { id: 3, name: 'Charlie', group: 'A' },
          // ... more data
        ];

        const groupedData = data.reduce((acc, obj) => {
          const key = obj.group;
          if (!acc[key]) {
            acc[key] = [];
          }
          acc[key].push(obj);
          return acc;
        }, {});

        console.log(groupedData);
      
    

In this example, we have an array of objects data, each with an id, name, and group property. We want to group these objects based on the group property.

We use the reduce method to iterate through the array and accumulate the grouped objects into a new object groupedData. For each object, we check if a key for the group already exists in the accumulator. If not, we create an empty array for that group. We then push the object into the array for that group.

Finally, we log the groupedData, which will show the objects grouped by the group property.

Conclusion

The reduce method is a powerful tool in JavaScript for performing complex operations on arrays, such as grouping objects based on a specific property. By understanding how to use reduce in combination with other array methods, you can efficiently manipulate and organize your data in your JavaScript applications.