Section 01 / Inside JavaScriptHow it works:
How it works:
JavaScript Engine
From a line of code to a running program.
We will explore the engine step by step, using examples and interactive diagrams.
19 lessons~60–90 minutes including practiceECMA-262 + V8
Start section →Core engine mechanisms
Source → AST → Bytecode
Ignition ↔ JIT
Call Stack + Memory Heap
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Lessons can be opened individually or followed in order- 01ECMAScript · Engine · RuntimeLanguage, engine, and runtime✓
- 02OverviewHow V8 executes JavaScript✓
- 03Source text → tokensScanner: recognizing language elements✓
- 04Syntax treeAST: the structure of a program✓
- 05Startup and lazy parsingNot everything needs compiling at startup✓
- 06AST → instructionsBytecode: instructions for Ignition✓
- 07Executing bytecodeHow an interpreter works✓
- 08Bytecode → machine codeJIT: why V8 has several compilers✓
- 09Feedback → specialization → deoptOptimization relies on assumptions✓
- 10Call → returnCall Stack: which function is running✓
- 11Arguments and returnStack frame: the state of a function call✓
- 12Objects and referencesMemory Heap: where objects are stored✓
- 13An object and its referenceChanging an object or replacing a reference?✓
- 14ReachabilityGC finds reachable objects✓
- 15Scene lifecycleMemory leaks: a reference keeps the object alive✓
- 16ThreadsJavaScript threads✓
- 17Practical diagnosisGame performance✓
- 18RecapHow the engine works: a recap✓
- 19Self-checkCheck your understanding✓