paulfranco

JavaScript Interview Questions

Q1: Explain equality in JavaScript ☆

Answer: JavaScript has both strict and type–converting comparisons:

• Strict comparison (e.g., ===) checks for value equality without allowing coercion
• Abstract comparison (e.g. ==) checks for value equality with coercion allowed

paulfranco

Interview Questions

MongoDB

Q1: Explain what is MongoDB? ☆

Answer: MongoDB is an open-source document database that provides high performance, high availability, and automatic scaling. It's Key Features are:

• Document Oriented and NoSQL database.

paulfranco

Interview Questions

Node.js

Q1: What do you mean by Asynchronous API? ☆☆

Answer: All APIs of Node.js library are aynchronous that is non-blocking. It essentially means a Node.js based server never waits for a API to return data. Server moves to next API after calling it and a notification mechanism of Events of Node.js helps server to get response from the previous API call.

Source: tutorialspoint.com

bradtraversy

MongoDB Cheat Sheet

Show All Databases

show dbs

Show Current Database

cdiggins

React Best practices

I have summarized and compiled a list of React.JS best practices from various sources across the internet.

From the React docs

• https://reactjs.org/docs/components-and-props.html

  • props must be readonly

• https://reactjs.org/docs/state-and-lifecycle.html

delibytes

React & JSX Cheatsheet

Overview
JSX HTML	<div>...</div>
JSX Component	<Component property={javascript} /> <Component property='string' />
JSX Component with Children	<Component>{children}</Component> reference: props.children
Escaping JavaScript	{...}
require statements	const React = require('react'); const ReactDOM = require('react-dom');
npm modules	react, react-dom

int128

Create React App does not provide watching build mode oficially (#1070).

This script provides watching build mode for an external tool such as Chrome Extensions or Firebase app.

How to Use

Create a React app.

Put the script into scripts/watch.js.

bvaughn

React lifecycle cheatsheet

Method	Side effects1	State updates2	Example uses
Mounting
componentWillMount		✓	Constructor equivalent for createClass
render			Create and return element(s)
componentDidMount	✓	✓	DOM manipulations, network requests, etc.
Updating
componentWillReceiveProps		✓	Update state based on changed props

augbog

Free O'Reilly books and convenient script to just download them.

Thanks /u/FallenAege/ and /u/ShPavel/ from this Reddit post

How to use:

1. Take the download.sh file and put it into a directory where you want the files to be saved.
2. cd into the directory and make sure that it has executable permissions (chmod +x download.sh should do it)
3. Run ./download.sh and wee there it goes. Also if you do not want all the files, just simply comment the ones you do not want.

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?