Filtering Array of Objects with Arrays Based on Nested Value

You are trying to filter an array of objects based on a nested value within those objects. The goal is to create a new array that includes only the objects with a specific value for a nested property.

To achieve this, you have used the following formula:

let filteredArray = arrayOfElements.filter((element) => element.subElements.some((subElement) => subElement.surname === 1));

This formula filters out the objects from the original array that have at least one sub-element with a surname property equal to 1. However, the output is not quite what you expected. Instead of removing the sub-elements that do not match the filter condition, it returns objects with all of the sub-elements, including those that do not match.

To improve the filtering, you can use a mapping function instead of a filter function. This will allow you to create a new array by transforming each element in the original array. The transformed element will include only the sub-elements that match the filter condition.

Here's an improved formula using the mapping function:

let filteredArray = arrayOfElements.map((element) => {
  return {...element, subElements: element.subElements.filter((subElement) => subElement.surname === 1)}
})

In this improved formula:

• The map function iterates over each element in the arrayOfElements array.
• For each element, it creates a new object that includes the original element's properties and a filtered subElements array.
• The filter function is applied to the subElements array to remove any sub-elements that do not match the filter condition, which is subElement.surname === 1 in this case.
• The spread operator (...) is used to create a new object that combines the original element's properties with the filtered subElements array.

This improved formula will return an array that includes only the objects that have at least one sub-element with a surname property equal to 1, and each object will only have the matching sub-elements included.