Full-Stack Developer

console.log(0.1 + 0.2);

console.log(0.4 + 0.1 == 0.5);

This is a trick question in that at first glance, you might expect the console to print out “0.3” and “true.” The correct answer is that you can’t know for sure, because of how JavaScript treats floating point values. In fact, in the above example, it will print out:

0.30000000000000004

false

var lorem = { ipsum : 1};

var output = (function(){

delete lorem.ipsum;

return lorem.ipsum;

})();

console.log(output);

The output would be undefined, because the delete operator removed the property “ipsum” from the object “lorem” before the object was returned. When you reference a deleted property, the result is undefined.

The great thing about JavaScript is the ability to do away with the rigid rules of classical inheritance and let objects inherit properties from other objects.

☛ Classical Inheritance: A constructor function instantiates an instance via the “new” keyword. This new instance inherits properties from a parent class.

☛ Prototypal Inheritance: An instance is created by cloning an existing object that serves as a prototype. This instance—often instantiated using a factory function or “Object.create()”—can benefit from selective inheritance from many different objects.

This question may seem self-explanatory, but what you’re looking for is a developer who can demonstrate solid understanding of how data flows throughout the application. In two-way data binding, changes to the UI and changes to the model occur asynchronously—a change on one end is reflected on the other. In one-way data binding, data only flows one way, and any changes that the user makes to the view will not be reflected in the model until the two are synced. Angular makes implementing two-way binding a snap, whereas React would be your framework of choice for deterministic one-way data flow.

Prototypal OO is the other major programming paradigm that really lets JavaScript shine—objects linked to other objects (OLOO). You’re looking for knowledge of when and where to use prototypes, liberal use of “Object.assign()” or mixins, and a solid grasp of concepts like delegation and concatenative inheritance.

Specification describes a modular system and a service platform for the Java programming language that implements a complete and dynamic component model. Each bundle has its own classpath. Dependency hell avoidance. META-INF/MANIFEST.MF contains OSGI-info

Variable of type Shape could refer to an object of type Square, Circle... Ability of a function to handle objects of many types

a problem encountered in concurrent computing where a process is perpetually denied necessary resources to process its work

A palindrome is a word, phrase, or sequence of letters that reads the same backwards or forwards. It also makes a great test for checking their ability to handle strings.

function isPalindrome(str) {

str = str.replace(/s/g, '').toLowerCase();

return (str == str.split('').reverse().join(''));

}

There are many jobs associated with putting together an application, and chances are high that your new JavaScript developer will at the very least have to interface with a designer. You’re looking for a developer who can communicate effectively when they need to, responds to emails, and knows how to coordinate with other branches of a project.

You can tell a lot about a programmer from the frameworks they’re familiar with—AngularJS, React, jQuery, Backbone, Aurelia, and Meteor are just some of the more popular ones available. The key here is to make sure the developer you’re engaging has experience with the framework you’ve chosen for your project.

Experienced coders won’t just be able to rave about their favorite language’s strengths—they will also be able to talk about its weaknesses. JavaScript’s main weakness is security. Look for answers on how it can be exploited. A secondary weakness is JavaScript’s ubiquity and versatility—it can be a double-edged sword in that there’s a lot of room for programming quirks that can lead to inconsistent performance across different platforms.

Functional programming is one of the key paradigms that makes JavaScript stand out from other languages. Look for examples of functional purity, first-class functions, higher-order functions, or using functions as arguments and values. It’s also a good sign if they have past experience working with functional languages like Lisp, Haskell, Erlang, or Clojure.

REST stands for Representational State Transfer, an architectural style that has largely been adopted as a best practice for building web and mobile applications. RESTful services are designed to be lightweight, easy to maintain, and scaleable. They are typically based on the HTTP protocol, make explicit use of HTTP methods (GET, POST, PUT, DELETE), are stateless, use intuitive URIs, and transfer XML/JSON data between the server and the client.

Can be safely invoked by multiple threads at the same time

Growing phase, shrinking phase. Guarantees serializablity for transactions, doesn't prevent deadlock