maxBy | /lib/std/collections.ts | molt@0.17.2

function maxBy

import { maxBy } from "https://deno.land/x/molt@0.17.2/lib/std/collections.ts";

maxBy<T>(array: Iterable<T>, selector: (el: T) => number): T | undefined

Returns the first element that is the largest value of the given function or undefined if there are no elements.

maxBy<T>(array: Iterable<T>, selector: (el: T) => string): T | undefined

Returns the first element that is the largest value of the given function or undefined if there are no elements.

maxBy<T>(array: Iterable<T>, selector: (el: T) => bigint): T | undefined

Returns the first element that is the largest value of the given function or undefined if there are no elements.

maxBy<T>(array: Iterable<T>, selector: (el: T) => Date): T | undefined

Returns the first element that is the largest value of the given function or undefined if there are no elements.

Examples

Example 1

import { maxBy } from "https://deno.land/std@0.224.0/collections/max_by.ts";
import { assertEquals } from "https://deno.land/std@0.224.0/assert/assert_equals.ts";

const people = [
  { name: "Anna", age: 34 },
  { name: "Kim", age: 42 },
  { name: "John", age: 23 },
];

const personWithMaxAge = maxBy(people, (i) => i.age);

assertEquals(personWithMaxAge, { name: "Kim", age: 42 });

Type Parameters

Parameters

array: Iterable<T>

selector: (el: T) => number

Returns

T | undefined

Returns the first element that is the largest value of the given function or undefined if there are no elements.

Examples

Example 1

import { maxBy } from "https://deno.land/std@0.224.0/collections/max_by.ts";

const people = [
  { name: "Anna" },
  { name: "Kim" },
  { name: "John" },
];

const personWithMaxName = maxBy(people, (i) => i.name);

import { maxBy } from "https://deno.land/std@0.224.0/collections/max_by.ts";
import { assertEquals } from "https://deno.land/std@0.224.0/assert/assert_equals.ts";

const people = [
  { name: "Anna", age: 34n },
  { name: "Kim", age: 42n },
  { name: "John", age: 23n },
];

const personWithMaxAge = maxBy(people, (i) => i.age);

assertEquals(personWithMaxAge, { name: "Kim", age: 42n });

import { maxBy } from "https://deno.land/std@0.224.0/collections/max_by.ts";

const people = [
  { name: "Anna", startedAt: new Date("2020-01-01") },
  { name: "Kim", startedAt: new Date("2021-03-01") },
  { name: "John", startedAt: new Date("2020-03-01") },
];

const personWithLastStartedAt = maxBy(people, (i) => i.startedAt);