array.prototype.flatmap provides a polyfill for the flatMap method, which exists natively in modern JavaScript environments. This method combines the functionality of map and flat in a single step, transforming each element of an array using a mapping function, and then flattening the result into a new array. This simplifies code that requires both mapping and flattening, enhancing readability and performance. It is especially beneficial when dealing with nested arrays or data structures that need to be processed in a chained manner.
The npm package array.prototype.flatmap saw initial active development with multiple releases from October 2017 to February 2018. After a period of inactivity, releases became less frequent, occurring sporadically from October 2019 to December 2024. No releases have occurred in the first nine months of 2025.
Array.prototype.flatmap npm package downloads show consistent growth, exceeding 100 million monthly downloads since October 2024. Downloads peaked in July 2025 at 146 million. September 2025 downloads are significantly lower, likely due to incomplete data for the month.
