js-subtype

js-subtype is a lightweight library that allows you to determine JavaScript subtypes, making it easy to identify the exact type of an object (like Array, Date, etc.).

Features

• Supports multiple subtypes (Array, Date, Map, RegExp, etc.).
• Lightweight and easy to use.
• Zero dependencies.
• Works in both Node.js and modern browsers.

Installation

Install using npm:

npm install js-subtype

Or with yarn:

yarn add js-subtype

Usage

Here’s a quick example of how to use js-subtype:

const { getType } = require("js-subtype");

console.log(getType([1, 2, 3])); // Output: "Array"
console.log(getType(new Date())); // Output: "Date"
console.log(getType(/regex/)); // Output: "RegExp"

API

getType(value)

Returns a string representing the subtype of the given value.

• Parameters:
  • value: Any JavaScript value.
• Returns: The string subtype (Array, Date, Map, etc.).

Use Cases

Advanced Type Validation

Use js-subtype to validate inputs or types precisely in your applications:

function validateInput(input) {
  if (getType(input) !== "Array") {
    throw new Error("Input must be an array.");
  }
  // Additional logic...
}

Type	Subtype	Description
undefined	undefined	Undefined value.
boolean	boolean	Boolean value (true or false).
number	integer	Integer number.
number	float	Floating-point number.
string	string	Text string.
object	null	Null value.
object	array	Array (list of elements).
object	date	Date object.
object	regexp	Regular expression.
object	map	Map object.
object	set	Set object.
object	weakmap	WeakMap object.
object	weakset	WeakSet object.
object	error	Error object.
object	promise	Promise object.
object	object	Generic object.
function	function	Function.
symbol	symbol	Symbol (Symbol).
bigint	bigint	Large integer (BigInt).

Identifying Native JavaScript Objects

Determine the exact native type of an object, such as Map or Set:

console.log(getType(new Map())); // Output: "Map"
console.log(getType(new Set())); // Output: "Set"

License

This project is licensed under the MIT License.