To-type NPM | npm.io

to-type

The way typeof should be

A JavaScript implementation of angus-c's Fixing the JavaScript typeof operator.

Install

Node

npm install --save to-type

Web

<script src="https://rawgit.com/dawsonbotsford/to-type/master/bundle.js"></script>

Alternatively, you can install the npm module and reference the bundle within node_modules

<script src="<path to node_modules>/to-type/bundle.js"></script>

Usage

// Remove this require line if you're using the web bundle (it's already bundled as "to-type")
const to-type = require('to-type');

toType([1, 2, 3]);
//=> 'array'

toType(/a-z/);
//=> 'regexp'

toType(new Number(4));
//=> 'number'

toType(new String('abc'));
//=> 'string'

About

JavaScript's typeof function sucks. It has returned vague values since 1997 and always will be due to backwards compatibility. It seems like nearly every call returns object. Don't believe me?

typeof {a: 4};
//=> 'object'

typeof [1, 2, 3];
//=> 'object'

typeof new ReferenceError;
//=> 'object'

typeof new Date;
//=> 'object'

typeof /a-z/;
//=> 'object'

typeof JSON;
//=> 'object'

typeof new Number(4);
//=> 'object'

typeof new String('abc');
//=> 'object'

Did I hear you say that was not enough proof?

typeof new Boolean(true);
//=> 'object'

Wait, you're still not convinced?

typeof Math;
//=> 'object'

to-type fixes these vague outputs by returning the types you expect to see.

API

toType(target)

target

Type: all types

returns

Type: string

Description: The return value is always lowercased.

More Examples

toType({a: 4});
//=> 'object'

toType(new Date());
//=> 'date'

toType(Math);
//=>'math'

toType(JSON);
//=> 'json'

toType(new Number(4));
//=> 'number'

toType(new String('abc'));
//=> 'string'

toType(new Boolean(true));
//=> 'boolean'

toType(new ReferenceError());
//=> 'error'


//es2015 and newer
toType(Promise);
//=> 'function'

toType(Symbol());
//=> 'symbol'