std/collections/mod.ts

Deno standard library
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function distinctBy
import { distinctBy } from "https://deno.land/std@0.139.0/collections/mod.ts?s=distinctBy";

Returns all elements in the given array that produce a distinct value using the given selector, preserving order by first occurrence

Example:

import { distinctBy } from "https://deno.land/std@0.139.0/collections/mod.ts";
import { assertEquals } from "https://deno.land/std@0.139.0/testing/asserts.ts";

const names = [ 'Anna', 'Kim', 'Arnold', 'Kate' ]
const exampleNamesByFirstLetter = distinctBy(names, it => it.charAt(0))

assertEquals(exampleNamesByFirstLetter, [ 'Anna', 'Kim' ])

Parameters

array: readonly T[][src]
selector: (el: T) => D[src]