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Module

std/collections/max_by.ts>maxBy

Deno standard library
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The Standard Library has been moved to JSR. See the blog post for details.
function maxBy
import { maxBy } from "https://deno.land/std@0.217.0/collections/max_by.ts";

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@0.217.0/collections/max_by.ts";
import { assertEquals } from "https://deno.land/std@0.217.0/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 });

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@0.217.0/collections/max_by.ts";

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

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

Parameters

array: Iterable<T>
selector: (el: T) => string

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@0.217.0/collections/max_by.ts";
import { assertEquals } from "https://deno.land/std@0.217.0/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 });

Parameters

array: Iterable<T>
selector: (el: T) => bigint

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@0.217.0/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);

Parameters

array: Iterable<T>
selector: (el: T) => Date

Returns

T | undefined