castArray (Lodash Compatibility)

Use Array.from() or array literals ([value])

This castArray function behaves complexly due to no-argument handling and undefined processing.

Instead, use the clearer and more modern Array.from() or conditional array creation (Array.isArray(value) ? value : [value]).

Converts a value to an array if it's not already an array.

const result = castArray(value);

Reference

castArray(value?)

Use castArray when you want to ensure any value becomes an array. If the value is already an array, it returns as is. Otherwise, it creates a new array containing that value.

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

// Convert a number to an array
castArray(1);
// Returns: [1]

// Convert a string to an array
castArray('hello');
// Returns: ['hello']

// Convert an object to an array
castArray({ a: 1 });
// Returns: [{ a: 1 }]

Values that are already arrays are returned as is.

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

castArray([1, 2, 3]);
// Returns: [1, 2, 3]

castArray(['a', 'b']);
// Returns: ['a', 'b']

null and undefined are also converted to arrays.

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

castArray(null);
// Returns: [null]

castArray(undefined);
// Returns: [undefined]

When called without arguments, returns an empty array.

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

castArray();
// Returns: []

Parameters

• value (T | readonly T[], optional): The value to convert to an array. If no argument is provided, returns an empty array.

Returns

(T[]): Returns the array if the input is already an array, otherwise returns a new array containing the input value.