What is the recommended way to filter Objects with Unique property in the array in JS?

Question

How to filter objects in array based on unique property here i have an array where KEY is the key value in the objects. How to filter the objects where key value is unique. Key

Answer 1

Here is a ES6 version filter utility:

// Unique is only that item, if we find him in array on the same index.
const onlyUniqueProperty = prop => (value, index, self) =>
    self.findIndex(item => item[prop] === value[prop]) === index;

// Usage:
const uniqueItems = items.filter(onlyUniqueProperty('key'));

If we want to support both JS and Immutable.js objects, small update:

const getProp = (obj, prop) => typeof obj.get === 'function' ? obj.get(prop) : obj[prop];

// Unique is only that item, if we find him in array on the same index.
const onlyUniqueProperty = prop => (value, index, self) =>
    self.findIndex(item => getProp(item, prop) === getProp(value, prop)) === index;

// Usage:
const uniqueItems = items.filter(onlyUniqueProperty('key'));