Do less work in JavaScript: lazy data pipelines with iterator helpers instead of arrays.

Matt Smith

JavaScript iterator helpers provide a lazy alternative to eager array methods, processing data only when needed. Instead of creating multiple intermediate arrays with `.map().filter().slice()`, iterator helpers like `.values().filter().map().take()` stop early and avoid unnecessary work. This is particularly useful for large datasets, virtualized lists, infinite scrolling, and streaming APIs. While arrays remain better for small datasets and random access patterns, iterator helpers reduce memory allocation and computation by matching how UIs actually consume data. Supported in modern browsers (Chrome 122+, Firefox 131+, Safari 18.4+) and Node.js 22+.

Stop turning everything into arrays (and do less work instead)

Arrays everywhere (and way more work than necessary)