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Cheatsheets for programming languages

Java Cheatsheet

Intro to Java

Hello World Variables Object-Oriented Java

Learn Java: Basic Control Flow and Operators

Understanding Conditionals

Learn Java

Basic Loops in Java Working with Strings Understanding Access, Encapsulation, and Static Methods Basics of Inheritance and Polymorphism Working with Two-Dimensional Arrays

Java for Programmers

Basic Syntax in Java Arrays in Java Object-Oriented Programming in Java Java's Built-In Data Structures

Learn Java: Object-Oriented Programming

What Are Classes, Objects, and Methods? Using Built-In Classes

Learn Java: Basics of Classes, Methods, Inheritance, and Polymorphism

String Methods Access, Encapsulation, and Static Methods Inheritance and Polymorphism

Learn Java: Loops and Arrays

Arrays and ArrayLists Loops Two-Dimensional Arrays

Learn Java: Understanding Inheritance and Polymorphism

Inheritance Basics Polymorphism

Learn Intermediate Java

Working with Input and Output Understanding Serialization Using Generics and Collections Basics of Threading

Learn Intermediate Java: Input and Output

Input and Output Basics

Learn Intermediate Java: Serialization

Serialization Basics

Learn Intermediate Java: Generics and Collections

Generics and Collections

Learn Java: Understanding Threads

Basics of Threads in Java

Learn Spring Framework

Introduction to Spring Working with Controllers Understanding Beans and Boot Data Management Spring Data and JPA

Learn Spring: Fundamentals and Controllers

Introduction to Spring Understanding Spring Controllers

Learn Spring: Building an App

Boots and Beans Data Strategies Spring Data and JPA

Mastering Java Programming

Multithreading and Concurrency Web Programming with Servlets Network Programming with Sockets Using Native Code with Java (JNI) Database Connectivity with Java (JDBC)

HTML and CSS Cheatsheet

Learn HTML

Elements and Structure Tables Forms Semantic HTML

Beginner HTML

Basic HTML Elements Creating Tables

Learn HTML: Fundamentals

Elements and Structure

Learn HTML: Tables

Learn HTML: Forms

Learn HTML: Making Web Pages Meaningful

Understanding Semantic HTML

HTML: Tables and Forms

Understanding HTML Tables Understanding HTML Forms

Learn CSS

CSS Basics Styling Text Box Model Layouts Colors Typography

Beginner CSS

Styling a Website

Basic Styling Concepts

Understanding Box Model and Layout Basics

Understanding the Box Model Basics of Display and Positioning

CSS Layout and Positioning

The Box Model Display and Positioning

Understanding Responsive Design with CSS

Basics of Responsive Design

Responsive Design and Accessibility

Learn Responsive Design

Learn Intermediate CSS

Layout with Flexbox Grid Layout CSS Transitions Responsive Design

Understanding Colors in CSS

Basic Color Concepts

CSS for Colors and Text Styles

Colors in CSS Text Styles in CSS

Basics of CSS: Fonts and Text Styling

Typography in CSS

Advanced CSS: Flexbox and CSS Transitions

Understanding Flexbox Layout Using CSS Transitions

Getting Started with CSS Transitions and Animations

Introduction to CSS Transitions

Learn CSS: Flexbox and Grid

Flexbox Layout Grid Layout

CSS Grid Layout

Getting Started with CSS Grid

Beginner's Guide to Advanced Web Design

Understanding the Box Model Working with Display and Positioning Exploring Colors Basics of Typography Introduction to Responsive Design Designing Layouts with Flexbox

Learn Website UI Design

Understanding Links and Buttons

Learn A-Frame (VR)

Getting Started with A-Frame

Python Cheatsheet

Introduction to Python

Python Basics: Lists Python Basics: Loops Python Basics: Functions Python Basics: Practice Challenges (Optional) Setting Up Python on Your Computer Python Basics: Strings Python Basics: Modules Python Basics: Dictionaries Introduction to Object-Oriented Programming

Learn Python Programming

Getting Started with Python Understanding Control Flow Using Loops Creating Functions Handling Strings Using Modules Working with Dictionaries Managing Files Understanding Classes

Learn Recursion with Python

Understanding Recursion Recursion in Python

Linear Data Structures

Understanding Nodes Linked Lists Basics Introduction to Stacks Understanding Queues

Learn Complex Data Structures

Learn Hash Maps Learn Trees Learn Heaps Learn Graphs

Learn Sorting Algorithms with Python

Bubble Sort Merge Sort Quicksort

How to Implement Search Algorithms with Python

Understanding Linear and Binary Search

Learn Statistics with Python

Mean, Median, and Mode Variance and Standard Deviation Histograms Describe a Histogram Quartiles, Quantiles, and Interquartile Range Boxplots

Learn Statistics with NumPy

Getting Started with NumPy Using NumPy for Statistics

How to Clean Data with Python

Understanding Regular Expressions

Learn Web Scraping with Beautiful Soup

Getting Started with Beautiful Soup

Text Preprocessing

Understanding Regular Expressions Basics of Text Preprocessing

Analyze Data with Python - Easy Hypothesis Testing with SciPy

Simple Hypothesis Testing

Analyze Data with Python - Simple Statistics

Understanding Variance and Standard Deviation Quartiles, Quantiles, and Interquartile Range Sample Mean vs. Population Mean and P-Values

Learn Data Analysis with Pandas

Introduction to Pandas Using Aggregates in Pandas Working with Multiple Tables in Pandas

Analyze Data with Python - NumPy for Beginners

Getting Started with NumPy Statistics with NumPy

Machine Learning: Supervised Learning

Simple Linear Regression Classifying with K-Nearest Neighbors K-Nearest Neighbor for Predictions Logistic Regression Explained Understanding Decision Trees Naive Bayes for Classification Minimax for AI Decision Making

Build a Machine Learning Model - Unsupervised Learning

Understanding Clustering

Machine Learning: Unsupervised Learning

Clustering: K-Means

Getting Started with Understanding Natural Language Processing

Introduction to Natural Language Processing

Learn Hardware Programming with CircuitPython

Circuit Playground Express: Basics

Learn the Basics of Blockchain with Python

Basic Blockchain Concepts

Build Chatbots with Python - Introduction to Python and Chatbots

Getting Started with Python and Comments Understanding Functions Control Flow Basics

Python Data Structures and Loops

Build Chatbots with Python - Rule-Based Chatbots

Understanding Natural Language Processing and Rule-Based Chatbots Getting Started with Regular Expressions Preparing Text for Chatbots Creating Rule-Based Chatbots

Build Chatbots with Python - Basics of Retrieval-Based Chatbots

Understanding Text with Basic Models Word Representation with Vectors How Retrieval-Based Chatbots Work

Build Chatbots with Python - Deep Learning and Generative Chatbots

Chatbots with Deep Learning Recurrent Neural Networks and Chatbots Generating Chatbot Responses Generative Chatbots

Javascript Cheatsheet

Understanding JavaScript: Conditionals and Functions

Conditionals Explained Working with Functions Getting Started with Arrays Introduction to Loops

Learn JavaScript: Functions and How They Work

Understanding Functions Understanding Scope

Learn JavaScript: Understanding Objects

Understanding JavaScript Objects

JavaScript Arrays and Loops: A Beginner's Guide

Understanding Arrays Understanding Loops

JavaScript Iterators, Objects, and Classes

Iterators Objects Classes

Learn jQuery: A Simple Guide

Introduction to jQuery Creating Effects with jQuery Handling Events in jQuery Changing Styles with jQuery Navigating the DOM with jQuery

Learn jQuery: Easy Styling Techniques

jQuery: Simple Style Methods

Learn jQuery: Navigating the DOM

jQuery: Navigating Through Elements

Learn JavaScript: Simple Guide to Promises and Async-Await

Understanding Promises Getting Comfortable with Async-Await

Learn JavaScript: Making Web Requests

Making Web Requests

Learn JavaScript Unit Testing

Writing Effective Tests with Mocha

Understanding JavaScript Errors and How to Handle Them

Errors and How to Handle Them

Understanding JavaScript Objects, Modules, and Browser Compatibility

JavaScript Objects Simplified Making Sure Your JavaScript Works in All Browsers

Understanding JavaScript: Making Your Code Work Everywhere

Making JavaScript Work on All Browsers

How to Build Websites on Your Own Computer

Using Command Line to Build Websites

C Cheatsheet

Learn C: Introduction

Introduction to C Programming

Learn C: Variables and Operators

Understanding Variables Understanding Operators

Learn C: Understanding Conditionals and Loops

Conditionals Loops

Learn C: Functions and Structures

Functions Structures

Learn C: Understanding Arrays and Strings

Basics of Arrays and Strings

Learn C: Pointers and Memory

Understanding Pointers and Memory

C++ Cheatsheet

Learn C++ Basics

Getting Started Working with Variables Making Decisions

Learn C++: Loops Explained for Beginners

Introduction to Loops

Learn C++: Functions

Understanding Functions in C++

Learn C++: References and Pointers

References and Pointers Basics

Learn C++: Classes and Objects

Classes and Objects

Learn C++: Working with Vectors

Understanding Vectors

DevOps Cheatsheet

Go Programming Basics: A Beginner's Guide

Introduction to Go Understanding Variables in Go Using the fmt Package in Go Working with Conditionals in Go Getting Started with Functions in Go

Learn Go: Understanding Conditional Statements

Introduction to Go Conditionals

Learn Go: Understanding Functions

Functions in Go

Learn Go: Understanding Loops

Learn Go: Understanding Loops Learn Go: Working with Arrays

Learn Go: Maps and Structs

Learn Go: Working with Maps Learn Go: Understanding Structs

Learn Bash Scripting: A Beginner's Guide

Introduction to Bash Scripting

Basics of Using the Command Line

How to Navigate the File System How to View and Change Files and Directories How to Redirect Output and Input Setting Up Your Command Line Environment

Introduction to DevOps

Understanding DevOps Culture Infrastructure Basics Monitoring Systems Building Resilient Systems CI/CD Pipelines Explained

Website Building and Styling

Introduction to Go Programming Understanding Variables in Go Using the fmt Package in Go

Cloud Cheatsheet

Introduction to Cloud Computing

What is Cloud Computing? Benefits and Drawbacks Types of Cloud Services

Cloud Service Models

Infrastructure as a Service (IaaS) Platform as a Service (PaaS) Software as a Service (SaaS)

Cloud Deployment Models

Public Cloud Private Cloud Hybrid Cloud Multi-Cloud

Cloud Providers Overview

Amazon Web Services (AWS) Microsoft Azure Google Cloud Platform (GCP) Other Providers

Virtualization and Containers

Virtual Machines (VMs) Containers and Docker Kubernetes in Cloud

Networking in Cloud

Virtual Private Cloud (VPC) Load Balancing Content Delivery Networks (CDNs)

Cloud Storage Options

Block Storage Object Storage File Storage Archival Storage

Cloud Security Fundamentals

Identity and Access Management (IAM) Encryption and Data Protection Compliance Standards

Serverless Computing

What is Serverless? Functions as a Service (FaaS) Popular Serverless Platforms

Infrastructure as Code (IaC)

What is IaC? Tools for IaC (Terraform, AWS CloudFormation) Benefits of IaC

Cloud Cost Management

Understanding Cloud Costs Cost Optimization Strategies Tools for Cost Management

Cloud Monitoring and Logging

Importance of Monitoring Tools and Services for Monitoring Log Management in Cloud

Cloud Data Management

Data Lifecycle Management Data Lakes and Warehouses Data Migration Tools

High Availability and Disaster Recovery

Ensuring High Availability Disaster Recovery Planning Backup Solutions

Cloud Compliance and Governance

Understanding Compliance Governance Frameworks Auditing in Cloud

Kubernetes Cheatsheet

Kubernetes Cluster Components

Control Plane Components Worker Node Components

Pods and Pod Management

Pod Basics Multi-Container Pods Pod Lifecycle

Deployments and ReplicaSets

Deployment Basics Scaling Deployments Rolling Updates Reverting Changes

Services and Networking

Service Types DNS-Based Service Discovery Ingress and Load Balancing

ConfigMaps and Secrets

ConfigMap Basics Using ConfigMaps in Pods Managing Secrets Securely

Stateful Workloads

StatefulSets Overview Persistent Volumes and Claims Managing Stateful Applications

Scaling and Autoscaling

Horizontal Pod Autoscaling (HPA) Vertical Pod Autoscaling (VPA) Cluster Autoscaler

Kubernetes Networking

CNI Plugins and Network Configuration Service Mesh Overview (Istio, Linkerd) Network Troubleshooting

Kubernetes Monitoring and Logging

Monitoring with Prometheus Logging with Fluentd and Elasticsearch Using Grafana for Visualization

Security in Kubernetes

Role-Based Access Control (RBAC) Network Policies Pod Security Standards

Helm and Package Management

Introduction to Helm Using Helm Charts Managing Releases

CI/CD with Kubernetes

Building CI/CD Pipelines with Jenkins X Integrating GitOps with ArgoCD Using Tekton for Kubernetes-native CI/CD

Kubernetes Operators and CRDs

Introduction to Operators Creating Custom Resource Definitions (CRDs) Managing Applications with Operators

Docker Cheatsheet

Introduction to Docker

What is Docker? Docker vs. Virtual Machines Benefits of Docker

Docker Images and Containers

Understanding Images Building Docker Images Managing Containers

Docker Networking

Bridge Networks Host Networks Custom Docker Networks

Docker Compose

What is Docker Compose? Writing a Compose File Running Multi-Container Applications

Docker Registry and Image Management

Understanding Docker Registries Pushing and Pulling Images Managing Images in a Registry

Docker Storage Drivers and Volumes

Overview of Docker Storage Drivers Choosing the Right Storage Driver Using Docker Volume Drivers

Docker Swarm and Orchestration

Introduction to Docker Swarm Swarm Mode Commands Deploying Services in a Swarm

Docker Secrets and Configuration Management

Introduction to Docker Secrets Creating and Using Secrets Managing Docker Configurations

Docker Networking Advanced

Overlay Networks Macvlan Networks Network Security in Docker

Docker Security

Securing Docker Images Docker Content Trust User Namespaces and Access Control

Docker API and CLI Tips

Using the Docker API Advanced Docker CLI Commands CLI Tips and Tricks

Machine Learning Cheatsheet

Introduction to Understanding Human Language with Python

Getting Started with Natural Language Processing

Learn R

Learn R: Introduction Learn R: Data Frames Learn R: Data Cleaning Learn R: Fundamentals of Data Visualization with ggplot2 Learn R: Aggregates Learn R: Joining Tables Learn R: Mean, Median, and Mode Learn R: Variance and Standard Deviation Learn R: Quartiles, Quantiles, and Interquartile Range Learn R: Hypothesis Testing

How to Use ChatGPT

What is ChatGPT? How ChatGPT Works Using ChatGPT Effectively Risks and Limitations Crafting Effective Prompts

Understanding Unsupervised Learning

Learning about Clustering

Linear Regression and Gradient Descent

Linear Regression Basics Gradient Descent in Python

Learn Linear Regression with R

Understanding Linear Regression in R

Understanding Logistic Regression in Machine Learning

Logistic Regression Basics

K-Nearest Neighbors in Machine Learning

K-Nearest Neighbors for Classification

Understanding Decision Trees and Random Forests

Understanding Perceptrons in Machine Learning

Perceptron Basics

Understanding Decision Making in AI with Minimax

How AI Makes Decisions with Minimax

Introduction to PyTorch and Neural Networks

Introduction to PyTorch and Neural Networks

PyTorch for Classification

Basics of Classification in PyTorch

Troubleshooting Cheatsheet

Website issues troubleshooting steps

Check browser console logs Inspect page load time Verify HTTP status codes Test browser compatibility Monitor SSL/TLS certificates Check DNS resolution Audit third-party scripts

Java troubleshooting steps

Check JVM logs Monitor memory usage Verify thread usage Inspect GC performance Review the database connection pool Analyze stack traces Check dependency conflicts

PHP troubleshooting steps

Check PHP error logs Inspect PHP configuration settings Monitor database queries Check file permissions Review PHP session management Inspect PHP FastCGI Process Manager (PHP-FPM) status Audit third-party libraries

Node.js troubleshooting steps

Check application logs Inspect event loop lag Monitor memory leaks Review asynchronous function performance Check database connection handling Audit NPM dependencies Monitor CPU usage

Server performance troubleshooting steps

Check CPU utilization Monitor disk I/O Review memory usage Analyze running processes Check network throughput Audit resource quotas Update server packages

Windows troubleshooting steps

Windows troubleshooting steps Check Event Viewer logs Monitor the Task Manager for resource usage Verify driver updates Inspect Windows update status Run System File Checker Review startup programs Check network configuration

Linux troubleshooting steps

Check system logs Monitor resource usage with top or htop Verify disk usage Inspect network connectivity Check process status Audit file permissions Update system packages

Network traffic troubleshooting steps

Monitor bandwidth usage Check packet loss Analyze network latency Inspect traffic load balancing Review quality of service (QoS) settings Track sudden spikes in traffic Monitor for DDOS attacks

Network configuration troubleshooting steps

Verify IP address configuration Check DNS settings Inspect firewall rules Review routing tables Check VPN or proxy settings Inspect NAT rules Audit VLAN configuration

AWS troubleshooting steps

Check EC2 instance health Monitor S3 bucket permissions Review AWS security groups Analyze CloudWatch logs Check IAM role permissions Monitor RDS performance Audit auto-scaling policies

Azure troubleshooting steps

Check Azure Monitor logs Verify VM status Review Azure NSGs Inspect Azure App Service health Monitor Azure Storage account usage Check Entra ID authentication Audit Azure resource quotas

Google Cloud Platform troubleshooting steps

Check Stackdriver logs Verify GCE instance health Analyze GCP VPC network connectivity Monitor Google Cloud SQL performance Inspect GKE status Track IAM role permissions Audit billing and resource usage

SD-WAN troubleshooting steps

Check the WAN link status Verify traffic prioritization rules Monitor bandwidth utilization Analyze network latency Inspect SD-WAN policy configuration Review edge device health Check for packet loss

Essentials kit

12 essential Docker commands for every DevOps and cloud engineer

docker run docker pull docker build docker ps docker exec docker logs docker stop docker rm docker rmi docker-compose up docker-compose down docker network create

10 key Kubernetes concepts every DevOps and sysadmin should master

Pods Namespaces Deployments Services ConfigMaps Secrets Ingress Horizontal Pod Autoscaler Persistent Volumes (PV) StatefulSets

Top 8 Terraform commands for effective infrastructure as code management

terraform init terraform plan terraform apply terraform destroy terraform fmt terraform validate terraform state terraform output

10 crucial Git commands every DevOps professional should know

git init git clone git add git commit git push git pull git branch git merge git stash git log

7 key Jenkins pipeline techniques for streamlined CI/CD

Declarative Pipelines Scripted Pipelines Parallel Stages Post Actions Pipeline as Code Parameterized Builds Using Shared Libraries

10 must-know Linux networking commands for sysadmins and DevOps engineers

ifconfig/ip ping traceroute netstat ss nslookup/dig curl/wget iptables tcpdump nmap

Top 10 Bash scripting practices for every DevOps and system administrator

Use #!/bin/bash Comment your code Use variables Error handling with set -e Input validation Use functions Check exit status ($?) Use trap for cleanup Use loops (for, while) Secure handling of user data

10 best practices for efficient CI/CD pipelines with GitLab

Use GitLab CI/CD Split jobs into stages Cache dependencies Parallel jobs Artifact management Environment variables Use runners efficiently Pipeline schedules Pipeline triggers Security scanning

Top 10 AWS CLI commands for every cloud and DevOps engineer

aws configure aws ec2 describe-instances aws s3 cp aws s3 sync aws ec2 start-instances aws ec2 stop-instances aws cloudformation deploy aws lambda invoke aws rds describe-db-instances aws iam create-user

Programming Cheatsheets: Quick Reference for Productivity

Welcome to our comprehensive collection of programming language cheatsheets! Whether you're a seasoned developer or a beginner, these quick reference guides provide essential tips and key information for all major languages. They focus on core concepts, commands, and functions—designed to enhance your efficiency and productivity.

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