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This is a playground to test code. It runs a full Node.js environment and already has all of npm’s 400,000 packages pre-installed, including estype with all npm packages installed. Try it out:

var estype = require("estype")

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estype v0.1.1

EcmaScript Type Checker


EcmaScript Type Checker.


Installing with npm:

$ npm install estype --save

This module does not have dependencies.


In a browser:

<script src="estype.js"></script>

In Node.js:

var type = require('estype');

Usage example:

var type = require('./estype');

var today = new Date();
if (type(today) === 'Date') {
    console.log('It\'s a date');

var obj = {};
if (type(obj) === 'Object') {
    console.log('It\'s an Object');

class MyClass extends Date {
var myObj = new MyClass();
if (type(myObj) === 'MyClass') {
    console.log('It\'s an instance of MyClass');

var result = Math.abs('text');
if (type(result) === 'NaN') {
    console.log('It\'s not a number');

Testing and complete reference of results

For testing and as a complete reference of available results, you can see


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