1 Languages
Every entry filed under Languages and its subtopics.
What kind of help
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.
55 entries match these filters
- 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
- 0004 Logging instead of print The logging module gives every message a level, a timestamp and a destination you can change without editing code. It is the… Intermediate · Explains an idea · Any system Article Files & automation 15 Oct 2026
- 0018 Promises and async/await explained A promise is a placeholder for a value that arrives later. async/await lets you write code that waits for promises as if… Intermediate · Explains an idea · Any system Article Async code 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
- 0009 CSV to JSON converter A small command-line tool that turns a CSV file into a JSON array of objects, with optional number detection, custom delimiters and… Beginner · Step by step · Any system Script CSV & JSON · Files & automation 15 Oct 2026
- 0019 fetch with timeout, retries and proper error handling A reusable fetchJson helper for Node 20+ and browsers that adds a timeout, retries with backoff for temporary failures, and clear errors… Intermediate · Step by step · Any system Script Async code · Making requests 15 Oct 2026
- 0029 TypeScript Microsoft's TypeScript language and compiler: typed JavaScript that compiles to plain JavaScript, plus the language service that powers editor features. Any system Repo Basics 15 Oct 2026
- 0010 Find duplicate files by content Scans folders and lists files with identical content, using file size first and SHA-256 hashes second. It is read-only and only reports… Intermediate · Step by step · Any system Script Files & automation 15 Oct 2026
- 0023 Run async tasks with a concurrency limit A small mapLimit helper that runs an async function over many items with at most N in flight, keeps result order, stops… Advanced · Step by step · Any system Script Async code 15 Oct 2026
- 0012 Requests: HTTP for humans Requests is the classic Python library for calling web APIs and downloading pages, with a simple API for GET and POST requests,… Any system Repo Files & automation · Making requests 15 Oct 2026
- 0030 Axios A promise-based HTTP client for browsers and Node.js with interceptors, automatic JSON handling, request cancellation and a consistent API in both environments. Any system Repo Async code · Making requests 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
- 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