operational problems are not really bugs but are problems attached to something else in our program. These are bugs and should be dealt with in our code. they can always be avoided by changing some line(s) of code.

a programming paradigm in which the flow of the program is determined by events.

Worker processes provide the execution environment for all web sites and applications configured in IIS.

Essentially you can have multiple jobs for node to process and it can handle it with no significant burden. This makes it scalable.

putting global packages in a single place in the system exactly where it depends on your set up.

RESTful web services are light weight, highly scalable and maintainable and are very commonly used to create APIs for web-based applications.



  1. 409 is the status code that would return.
  2. You would use the max width property in css.
  3. npm installs each package at a time. While yarn installs multiple packages simultaneously.
  4. You would automate the update you could use npm audit .This would report of security vulnerabilities.
  5. CHAR is fixed length while varchar is variable length.



arrow functions do not have prototype property. We do not have binding of this when an arrow is invoked through apply or call .Dec 14, 2020

the value of this inside an arrow function remains the same throughout the lifecycle of the function and is always bound to the value of this in the closest non-arrow parent function.

One is a function declaration , the other is a function expression.

Arrow functions are best for callbacks or methods like map, reduce, or forEach. You can read more about scopes on MDN.

destructing is a JavaScript expression that makes it possible to unpack values from arrays, or properties from objects , into distinct variables.

a closure gives you access to an outer function’s scope from an inner function.



Attributes are refering to additional information of an object. Properties are describing the characteristics of an object. Most people use these two words as synonyms

i would use for loop, for..in, for each..in, map, reduce etc.

the event loop continuously checks the call stack to see if there’s any function that needs to run. While doing so, it adds any function call it finds to the call stack and executes each one in order.

a job queue is a queue of things to do (usually stored persistant) and a call stack is a stack of routines. A job would have variables assigned to it, and a call stack would be the abstract implementation.

Es6 allows the developers to instantiate objects using the new operator. Es5 function focus on how the objects are instantiated.



The foreach() method returns undefined and map() returns a new array with the transformed elements

It is a process that starts with the element that triggered the event and then bubbbles up to the containing elements in the hierarchy.

A high order function is a function that receives a fucntion as an argument or returns the fucntion as output.

Associative array is an abstract data type that can hold data in (key, value) pairs.

An associative is an array which uses a string instead of a number as an index.



If you put use strict at the top of your code (or function), then the JS is evaluated in strict mode. Strict mode throws more errors and disables some features in an effort to make your code more robust, readable, and accurate.

Hoisting is a mechanism where variables and function declarations are moved to the top of their scope before code execution.

standards bodies create the standards that make our work as developers more efficient and make the technology we take advantage of as consumers possible.

ive had to take time away from my personal hobbies and give computer coding my full time to try to understand it the most Ican it truely has been a challenge.

It’s probable that you’ll encounter global variable name clashes. Since there’s only one namespace you’re more likely to double up on a variable name.