size (Lodash Compatibility)

::: warning Use .length property

This size function operates complexly due to null, undefined handling and support for various types.

Instead, use the faster and more modern .length property or Object.keys().length.

:::

Returns the size of arrays, strings, and objects.

const length = size(collection);

Usage

size(collection)

Use size to check the size of arrays, strings, objects, Maps, and Sets. It provides consistent size information for various types of collections.

import { size } from 'es-toolkit/compat';

// Number of elements in an array
size([1, 2, 3]);
// Returns 3

// Number of characters in a string
size('hello');
// Returns 5

// Number of enumerable properties in an object
size({ a: 1, b: 2, c: 3 });
// Returns 3

// Number of elements in a Map
size(
  new Map([
    ['a', 1],
    ['b', 2],
  ])
);
// Returns 2

// Number of elements in a Set
size(new Set([1, 2, 3]));
// Returns 3

null or undefined returns 0.

import { size } from 'es-toolkit/compat';

size(null); // 0
size(undefined); // 0
size({}); // 0
size([]); // 0

Parameters

• collection (object | string | null | undefined): The array, string, object, Map, or Set to check the size of.

Returns

(number): Returns the size of the collection. Returns 0 if null or undefined.