JavaScript Memory Management Explained: Stack vs Heap (First Principle) | Javascript Full Course #03

Ever wonder what actually happens when you declare a variable in JavaScript? Where does that data go? Why are some operations fast and others slow? The answer lies in the two "brains" of the JavaScript engine: the Stack and the Heap.
In this in-depth lecture, we'll demystify JavaScript memory management using first principles. Forget complex jargon—we'll use simple, powerful analogies (like a chef's kitchen) to give you a crystal-clear mental model of how your code runs. Understanding the Stack and Heap is the single most important step to moving from a beginner to an advanced JavaScript developer.
🎓 WHAT YOU WILL LEARN IN THIS VIDEO:
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Introduction: Why Memory Management Matters
The Two Brains of JavaScript: Stack vs. Heap
The Stack Explained (The Chef's Counter)
What is the Call Stack?
Why it's fast, organized, and uses LIFO (Last-In, First-Out).
How primitives (number, boolean) and references live on the stack.
Live trace: How the stack grows and shrinks with function calls.
The Heap Explained (The Restaurant's Pantry)
Why we need a separate space for objects and arrays.
How dynamic allocation works.
The role of the Garbage Collector.
Value vs. Reference: The Ultimate Explanation
Visualizing the difference between primitives (on the stack) and objects (on the heap).
Why const objects can be changed.
[00:00] How V8 Actually Stores Primitives (The Real Story)
The truth about Smis (Small Integers) vs. HeapNumbers.
How true, false, null, and undefined are optimized as singletons.
The Full Memory Hierarchy: From Hard Disk to CPU Cache
Why RAM is not enough and the role of CPU Cache.
How the stack's design makes your code faster.
👨‍💻 WHO IS THIS VIDEO FOR?
JavaScript beginners who want to understand the "why" behind the code.
Developers preparing for technical interviews where memory management is a key topic.
Anyone who wants to write more performant and bug-free JavaScript.





Course start date: 1 september
Timing: 6pm (Mon-fri)
Hackathon will be organised after course completion
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Time Stamp:

0:00 Introduction
2:22 RAM, Hard Disk, and CPU Interaction
5:03 Problem Statement: Managing Data Without Unique Identifiers
7:30 Solution: Byte-Addressable Memory
11:41 Understanding Address Sizes
13:44 How Programs Use Addresses
15:54 Introduction to Stack & Heap Memory
21:01 Why Stack and Heap Exist
24:49 Why Use Both Stack & Heap?
31:36 Fixed vs Dynamic Data Allocation
38:06 Why Store Addresses in the Stack
39:47 Dynamic Data Types in JavaScript
41:23 JavaScript Memory Allocation
45:01 Memory Allocation for Primitive Data Types
55:00 Optimizing Memory for true, false, null, and undefined
57:34 Memory Allocation for Objects
59:05 Garbage Collection: Cleaning Up Unused Memory
1:01:31 Loop Optimization
1:13:08 Encoding Data in Memory Addresses
1:21:47 Small Integers (SMIs) vs Larger Numbers
1:23:31 Memory Management Conclusion
1:24:35 Homework & Next Step
1:25:16 Wrapping Up


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