When we first start out learning to code we are concerned with just getting our function or simple application to run. The runtime of the different methods don’t matter much yet. As we soon learn, this is a very important concept to understand, and knowing how time works as it relates to an algorithm can allow one to make a much faster site/application/game when it comes to the algorithmic portion. Big-O notation was invented by Paul Bachmann and Edmund Landau and is the standard by which time is measured as the the input size grows by n. With n input…

Graphs and trees are central to the concept of data structures in computer science and represent a large category within the subject, among others like lists (arrays) and hashes. They are something many to-be employees at tech firms need to know well. Many interviewees find tree and graph questions to be some of the hardest problems to solve. Due to the nature of their structure it is trickier to traverse as opposed to a linear structure like an array or hash.


A tree is a structure comprised of nodes, with each node having zero or more children nodes. Another key…

Javascript has a built-in function that makes it tremendously easy to grab information from any website. Using fetch(www.exampleurl.com) you can retrieve just about anything (if it’s offered in the proper format) and re-render or reuse it for your program. Following the CRUD format I will go over the following fetch requests:

GET — Read

POST — Create

PATCH/PUT — Update

DELETE — Destroy

Every fetch request has the same basic structure: a URL to request data from, the type of request (it will default to GET), headers (typically the same, anything other than application/json is beyond the scope of this article), body (this is where you will set the change, for GET…

Most sites we visit in this day and age require some sort of login, or they don’t but it enhances the user experience if you make one. Using a basic email/password combination I will create a user and login, and apply principles from authentication, session and authorization in Rails.

To walk through the steps I’m going to make a new app and call it LoginApp, it will have two models; a User model and a Session model. Sessions will allow a user to navigate the site and be authorized to see certain content, content that is private to that specific…

Recently I’ve been spending a fair amount of time in this area of rails, and much of that time was spent learning as opposed to executing; so I felt imparting some of my newly found knowledge could save someone else a few hours as they slog through the same experience. (Looking at you, Bootcampers).

Forms are just that, a form that a user can fill out on an application. Typically when we think about forms we think a doctor’s office or a survey but we are inputting information into forms constantly. While I’m writing this article I am putting data…

Charlie Knight

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