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JS Engine ↔ Program to execute JS Source Code, consists of Call Stack, Heap, Callback Queue & Event Loop

aka JavaScript-Engine

Browser Vendor Engines

Call Stack​

where code executed via EC, to track execution order

Heap​

unstructured memory pool to store all Objects for app

Value​

immutable data saved at Memory Address

JS Compiler​

Program to transform JS Code, consists of Baseline Compiler, Optimization Compiler & Monitor

JIT​

Mix of Interpretation & Compiled Language, used by modern JS Engine, all code compiled & executed immediately

Interpretation​

Programming Language with Interpreter to parse & execute Source Code line by line

Compiler​

Program to translate Source Code to Machine Code (or IR)

Compilation vs Interpretation

References​

  1. Browser Runtime ↔ JS Runtime Environ with JS Engine, Web API, Callback Queue & Event Loop

  2. JavaScript Runtime ↔ Environ (container) to run JS, consists of JS Engine, JS Library & Platform-specific API

  3. Node.js Runtime ↔ JS Runtime Environ to execute JS outside Browser via JS Engine with C++ Bindings & Thread Pool

  4. Concurrency Model ↔ (mechanism) to achieve Concurrency for JS Engine via Event Loop, Callback Queue & Callback Function

  5. AST ↔ tree data struct to rep Source Code by organize JS Keywords for JS Engine

  6. JS Interpreter ↔ JS Engine Component to check AST for SyntaxError, handles ASI

  7. JIT ↔ Mix of Interpretation & Compiled Language, used by modern JS Engine, all code compiled & executed immediately

  8. Garbage-Collection ↔ 🧹Algorithm (in JS Engine) to remove old unused Object from Heap Memory

  9. InternalError ↔ Exception when exceed Call Stack size in JS Engine - when something too large || Infinite Loop

  10. Lexical Environment ↔ current Scope environ where JS Engine read Code

  11. getHeapStatistics() ↔ v8 Static Method to print stats for JS Engine

  12. V8 ↔ JS Engine of Google Chrome & Node.js

  13. Spidermonkey ↔ JS Engine to power Firefox, built in C++

  14. Safari ↔ default Apple OS Browser, Webkit JS Engine

  15. v8 ↔ Node API for V8 JS Engine