CodeOath
← All posts
JavaScript65 min total · 16 parts

JavaScript Array and Object Methods Cheat Sheet

Contents — Part 1 of 16: Overview
  1. 1.Overview
  2. 2.Mutating vs. Non-Mutating: The Distinction That Matters Most
  3. 3.Transforming Arrays
  4. 4.Searching and Testing Arrays
  5. 5.Iterating Arrays
  6. 6.reduce() in Depth
  7. 7.Object Methods
  8. 8.Spread and Rest
  9. 9.Destructuring
  10. 10.Optional Chaining and Nullish Coalescing
  11. 11.Equality: == vs. ===, and Comparing Objects
  12. 12.Map and Set: Alternatives to Plain Objects
  13. 13.JSON.stringify and JSON.parse
  14. 14.Shallow Copy vs. Deep Copy
  15. 15.A Worked Example Combining Several of These
  16. 16.Common Mistakes Worth Remembering
Part 1 of 16 · ~1 min

Overview

A handful of built-in methods cover the vast majority of everyday JavaScript data manipulation. This is a complete reference for the ones worth having memorized — not just what each does, but which ones mutate the original data, which return undefined on a miss, and where the common bugs hide.

Next →
Mutating vs. Non-Mutating: The Distinction That Matters Most