AIBeginner
Prompt Engineering 101Cheatsheet
A beginner guide to prompt structure, system instructions, few-shot examples, and chain-of-thought techniques for LLMs.
Useful Cheatsheets
Practical cheat sheets for everyday skills.
Direct and easy to read reference guides for everyday life — build software and AI systems, grow personal wealth and navigate taxes, and optimize your everyday health and wellness.
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Recent cheatsheets
EngineeringBeginner
Engine Basics 101Cheatsheet
A clear primer on four-stroke internal combustion cycles, core engine anatomy, and basic maintenance checkpoints.
EngineeringBeginner
Electric Motors 101Cheatsheet
A primer on DC and AC electric motors, electromagnetic induction, torque curves, and motor control circuits.
CodeAdvanced
JavaScript Currying and CompositionCheatsheet
Transform multi-argument functions into chained calls and combine small functions into pipelines.
CodeAdvanced
JavaScript Event LoopCheatsheet
Learn how the call stack, microtask queue, and task queue control JavaScript execution order.
CodeAdvanced
JavaScript GeneratorsCheatsheet
Learn how generator functions pause and resume execution to build lazy sequences and iterables.
CodeIntermediate
JavaScript Optional ChainingCheatsheet
Access nested properties safely with optional chaining and pair it with nullish coalescing for defaults.
CodeAdvanced
JavaScript Prototypal InheritanceCheatsheet
Understand the prototype chain, Object.create, and how class syntax wraps prototypal inheritance.
CodeAdvanced
JavaScript Proxy and ReflectCheatsheet
Learn how Proxy traps and the Reflect API intercept and control object behavior in JavaScript.
CodeAdvanced
JavaScript SymbolsCheatsheet
Use unique Symbol values as collision-free object keys and customize built-in object behavior.
CodeIntermediate
JavaScript TimersCheatsheet
Schedule code execution using setTimeout and setInterval, and rate-limit handlers using debounce and throttle patterns.
CodeIntermediate
JavaScript Type CoercionCheatsheet
Understand how JavaScript converts types automatically and avoid common equality and comparison bugs.
CodeAdvanced
JavaScript WeakMap and WeakRefCheatsheet
Store object-keyed data and hold references without blocking garbage collection in JavaScript.
CodeAdvanced
JavaScript Async IteratorsCheatsheet
Learn async iterators, async generators, and for await...of for consuming asynchronous data lazily.
CodeAdvanced
JavaScript Call Apply BindCheatsheet
Control the this keyword explicitly using call, apply, and bind on any function.
CodeIntermediate
JavaScript ClassesCheatsheet
Build objects with class syntax covering constructors, inheritance, static members, and private fields.
AIBeginner
Claude API BasicsCheatsheet
A quick reference for making your first Claude API call, picking a model, and reading the response.
AIIntermediate
Claude API Tool UseCheatsheet
A quick reference for defining tools, running the agentic loop, and using the SDK tool runner with Claude.
CodeAdvanced
TypeScript Utility TypesCheatsheet
A comprehensive reference for TypeScript built-in utility types like Partial, Pick, Omit, Record, and ReturnType.
CodeIntermediate
JavaScript Fetch APICheatsheet
Master the Fetch API for making HTTP requests in JavaScript, including GET, POST, error handling, and working with JSON responses.
CodeAdvanced
TypeScript Advanced TypesCheatsheet
A comprehensive guide to conditional types, mapped types, template literals, and type inference with infer.
CodeIntermediate
TypeScript Async PatternsCheatsheet
A developer guide to async/await, Promise types, error handling, and concurrency patterns in TypeScript.
CodeBeginner
TypeScript EnumsCheatsheet
A reference guide to TypeScript numeric enums, string enums, reverse mappings, and compile-time constants.
CodeAdvanced
TypeScript Function OverloadingCheatsheet
A reference guide to declaring and implementing TypeScript polymorphic function and method overloads.
CodeIntermediate
TypeScript Generics ConstraintsCheatsheet
A reference guide to TypeScript generic constraints using extends, keyof, constructor signatures, and intersections.
CodeIntermediate
TypeScript Null SafetyCheatsheet
A quick reference for handling null and undefined with optional chaining, coalescing, and strict guards.
CodeIntermediate
JavaScript ModulesCheatsheet
Organize JavaScript code with ES6 modules using named exports, default exports, and dynamic imports.
CodeAdvanced
JavaScript Regular ExpressionsCheatsheet
Learn regex patterns, flags, exec, test, match, and replace for powerful string processing.
CodeIntermediate
JavaScript Spread and RestCheatsheet
Use spread syntax to expand arrays and objects, and rest parameters to handle variable function arguments.
CodeBeginner
JavaScript StorageCheatsheet
Use localStorage and sessionStorage to persist data in the browser across sessions and refreshes.
CodeBeginner
JavaScript DestructuringCheatsheet
Master object and array destructuring for cleaner variable assignment and function parameters.
CodeIntermediate
JavaScript Error HandlingCheatsheet
Handle errors gracefully in JavaScript using try/catch, custom error classes, and finally blocks.