AlexJuca

Ruby on Rails Cheatsheet

Architecture

Create a new application

Install the Rails gem if you haven't done so before

AlexJuca

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?

AlexJuca

<!--- Provide a general summary of your changes in the Title above -->
<!--- If there is no changelog entry, label this PR as trivial to bypass the Danger warning -->

## Description

<!--- Describe your changes in detail -->

## Motivation and Context

<!--- Why is this change required? What problem does it solve? -->

AlexJuca

Postgres Cheatsheet

This is a collection of the most common commands I run while administering Postgres databases. The variables shown between the open and closed tags, "<" and ">", should be replaced with a name you choose. Postgres has multiple shortcut functions, starting with a forward slash, "". Any SQL command that is not a shortcut, must end with a semicolon, ";". You can use the keyboard UP and DOWN keys to scroll the history of previous commands you've run.

Setup

installation, Ubuntu

http://www.postgresql.org/download/linux/ubuntu/ https://help.ubuntu.com/community/PostgreSQL

AlexJuca

Software Engineering Excellency

DATA STRUCTURES

• Doesn’t know the difference between Array and LinkedList
• Able to explain and use Arrays, LinkedLists, Dictionaries etc in practical programming tasks
• Knows space and time tradeoffs of the basic data structures, Arrays vs LinkedLists, Able to explain how hashtables can be implemented and can handle collisions, Priority queues and ways to implement them etc.
• Knowledge of advanced data structures like B-trees, binomial and fibonacci heaps, AVL/Red Black trees, Splay Trees, Skip Lists, tries etc

ALGORITHMS

• Unable to find the average of numbers in an array

AlexJuca

Included here are the PowerShell profile I use as well as the oh-my-posh 3 config, but in addition to these you'll need:

1. The PowerShell modules:
   • For git in PowerShell, I use posh-git
   • For prompt customization, I use oh-my-posh
   • For file/folder icons I use the excellent Terminal-Icons package by @devblackops: https://github.com/devblackops/Terminal-Icons
   • To install each:

Install-Module -Name posh-git -Repository PSGallery
Install-Module -Name oh-my-posh -Repository PSGallery

AlexJuca

package des.c5inco.cardswipecompose

import androidx.compose.animation.core.*
import androidx.compose.animation.splineBasedDecay
import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.awaitFirstDown
import androidx.compose.foundation.gestures.verticalDrag
import androidx.compose.foundation.layout.*
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape

AlexJuca

:root {
    --bg-color: #ffffff;
    --font-color: #000000;
    /* highest contrast colors
    for light and dark themes */
    --red: #ec0000;
    --green: #008900;
    --blue: #5f5fff;
    --gray: #757575;
}

AlexJuca

Git Commit Best Practices

Basic Rules

Commit Related Changes

A commit should be a wrapper for related changes. For example, fixing two different bugs should produce two separate commits. Small commits make it easier for other developers to understand the changes and roll them back if something went wrong. With tools like the staging area and the ability to stage only parts of a file, Git makes it easy to create very granular commits.

Commit Often

Committing often keeps your commits small and, again, helps you commit only related changes. Moreover, it allows you to share your code more frequently with others. That way it‘s easier for everyone to integrate changes regularly and avoid having merge conflicts. Having large commits and sharing them infrequently, in contrast, makes it hard to solve conflicts.

AlexJuca

// Run in Swift Playground

import SwiftUI
import PlaygroundSupport

struct ContentView: View {
    var body: some View {
        Rectangle()
            .fill(Color.red)
            .frame(width: 200, height: 200)