Fermin Perdomo

Senior Full Stack Engineer | PHP | JavaScript

Today, I will explain how to unique an array of object by property

Unique by a Single PropertyIf you want the objects in the array to be unique based on one property (e.g., id):Unique by Multiple PropertiesIf you want uniqueness based on a combination of properties, you can create a unique key by combining the values of those properties:Using filter for SimplicityAlternatively, you can use the filter method for uniqueness by checking if an item's index matches its first occurrence:Explanation

  • Map and Set: Efficient for large arrays because they use hashing for uniqueness.

  • filter + findIndex: More readable but can be slower for large arrays due to nested iterations.

  • Custom Combination Key: Use when uniqueness depends on multiple properties.