1 Languages
Every entry filed under Languages and its subtopics.
What kind of help
Works on
What do these mean?
- Beginner
- You are new to this topic.
- Intermediate
- You use it, and want to get better.
- Advanced
- You know it well and need the details.
- Guided project
- Build something small from start to finish, step by step.
- Explains an idea
- Plain words on how something works and why.
- Step by step
- Numbered steps to get one task done.
- Cheat sheet
- Commands and options in a table, to look up fast.
- Fixes an error
- An error message, what it means, and how to solve it.
28 entries match these filters
- 0400 winget: install and update software from the command line winget is the package manager built into Windows. Search for a program, install it by id, update everything with one command and… Beginner · Step by step · Windows Article Installing languages & tools · Windows administration 15 Oct 2026
- 0394 Install kubectl on Linux, macOS and Windows Install the Kubernetes command-line client with curl, a package manager or winget, verify it, and point it at a cluster with a… Beginner · Step by step · Linux, macOS, Windows Article Concepts · Installing languages & tools 15 Oct 2026
- 0395 Install Rust on Linux, macOS and Windows Install Rust the official way with rustup, which brings rustc, cargo and future updates, make sure a C linker is present, and… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0386 Install Node.js on Linux, macOS and Windows Get Node.js and npm on any desktop OS. Use a version manager (nvm or fnm) when you work on several projects, or… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools · Node.js 15 Oct 2026
- 0388 Install Go on Linux, macOS and Windows Install the Go toolchain from the official downloads or a package manager, set PATH so the go command and installed tools are… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0389 Install Java (OpenJDK) on Linux, macOS and Windows Install a current long-term-support OpenJDK with the compiler included, make java and javac available on the command line, and switch between versions… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools 15 Oct 2026
- 0390 Install Git on Linux, macOS and Windows Install Git from your package manager, Xcode's command line tools or the Windows installer, confirm the version, and do the one-time configuration… Beginner · Step by step · Linux, macOS, Windows Article Installing languages & tools · Setup 15 Oct 2026
- 0391 Install Docker on Linux, macOS and Windows Docker Desktop or Docker Engine? Pick the right one for your OS, install it, and confirm with docker run hello-world. Covers the… Beginner · Step by step · Linux, macOS, Windows Article Docker basics · Installing languages & tools 15 Oct 2026
- 0387 Install Python on Linux, macOS and Windows Install a current Python 3 with pip and venv on each desktop OS, check the version, and avoid the classic traps: python… Beginner · Step by step · Linux, macOS, Windows Article Environments & packages · Installing languages & tools 15 Oct 2026
- 0392 Install Visual Studio Code on Linux, macOS and Windows Install VS Code from Microsoft's packages, Homebrew or winget, get the code command working in the terminal, and add the extensions you… Beginner · Step by step · Linux, macOS, Windows Article Command-line tools · Installing languages & tools 15 Oct 2026
- 0393 Install PostgreSQL on Linux, macOS and Windows Install the PostgreSQL server and the psql client on each desktop OS, start the service, connect as the postgres superuser and create… Beginner · Step by step · Linux, macOS, Windows Article Install & connect · Installing languages & tools 15 Oct 2026
- 0320 Fix: address already in use (EADDRINUSE) Something is already listening on the port your program wants. Find the process with lsof or ss, stop it or pick another… Beginner · Fixes an error · Linux, macOS Article Networking & firewalls · Node.js · Processes & ports 15 Oct 2026
- 0340 Build and run a small Python web app in a container Write a tiny Flask app, give it a Dockerfile, build the image, run it with a published port, make a change and… Beginner · Guided project · Linux, macOS, Windows Article Basics · Docker basics · Images & registries 15 Oct 2026
- 0319 Fix: npm ERR! EACCES permission denied npm cannot write to a directory it needs: the global install location, its cache in ~/.npm, or a node_modules owned by root.… Beginner · Fixes an error · Linux, macOS Article Common errors · Node.js 15 Oct 2026
- 0282 What is a dependency? A dependency is another piece of software your program needs to work, such as a library it imports. Beginner · Explains an idea · Any system Article Environments & packages 15 Oct 2026
- 0283 What is a virtual environment? A virtual environment is a private folder of Python packages for one project, so different projects never clash. Beginner · Explains an idea · Any system Article Environments & packages 15 Oct 2026
- 0261 Build a Python command-line to-do app: from empty folder to installable command Create a small to-do tool in Python with argparse and JSON storage, test it with pytest and package it with pyproject.toml so… Beginner · Guided project · Any system Article Environments & packages · Files & automation · Testing 15 Oct 2026
- 0073 Fix: json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0) Python's json module found nothing it could parse at the very first character. The input is usually empty, HTML, or already consumed.… Beginner · Fixes an error · Any system Article Common errors · CSV & JSON 15 Oct 2026
- 0008 Fix: TypeError: ‘NoneType’ object is not subscriptable You used [ ] on a value that is None. Something you expected to return a list, dict or match returned nothing.… Beginner · Fixes an error · Any system Article Common errors 15 Oct 2026
- 0016 let, const and var: variables and scope in JavaScript Use const by default, let when a value must change, and avoid var. The difference is about scope: where a variable is… Beginner · Explains an idea · Any system Article Basics 15 Oct 2026
- 0017 JavaScript array methods cheat sheet: map, filter, reduce and friends A quick reference for the array methods you use every day, with what each one returns and whether it changes the original… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0025 Regular expressions cheat sheet (JavaScript flavor) The regex syntax you actually use, from character classes and quantifiers to groups, lookarounds and flags, with the JavaScript methods that apply… Beginner · Cheat sheet · Any system Article Basics · Basics 15 Oct 2026
- 0026 Fix: TypeError: Cannot read properties of undefined (reading ‘x’) You tried to read a property from a value that is undefined or null. Find which value is missing, then guard it… Beginner · Fixes an error · Any system Article Basics · Common errors 15 Oct 2026
- 0024 TypeScript basics: types, interfaces, unions and narrowing TypeScript adds type annotations to JavaScript and checks them before your code runs. These are the core ideas you need to read… Beginner · Explains an idea · Any system Article Basics 15 Oct 2026
- 0007 Fix: ModuleNotFoundError: No module named ‘…’ Python cannot find a module you import. Usually the package was installed into a different interpreter or virtual environment than the one… Beginner · Fixes an error · Any system Article Common errors · Environments & packages 15 Oct 2026
- 0002 Python cheat sheet: strings, lists, dicts and f-strings The everyday methods for text, lists and dictionaries, plus f-string formatting and comprehensions, each with a one-line example you can paste into… Beginner · Cheat sheet · Any system Article Basics 15 Oct 2026
- 0001 Virtual environments with venv A virtual environment is a private folder of Python packages for one project, so projects never fight over versions. Create one with… Beginner · Explains an idea · Any system Article Environments & packages 15 Oct 2026
- 0003 pathlib cheat sheet: files and folders in Python pathlib.Path is the modern way to build paths, read and write files, and list or search folders in Python. This page lists… Beginner · Cheat sheet · Any system Article Files & automation 15 Oct 2026