#26 Stack and Heap in JAVA | Skyhighes | Lecture 26

Stack and Heap in Java: Memory Management Explained
In Java, your program's memory is divided into two main areas: the stack and the heap. These areas serve different purposes and manage memory differently.

Stack:

Imagine a stack of plates. Each plate represents a method call. As a method is called, its information (local variables, method arguments) is pushed onto the stack. When the method finishes, its information is popped off the stack.
The stack is used for short-lived data related to function calls. It's faster to access but has a limited size. Think of it as temporary workspace for ongoing tasks.
Each thread has its own private stack.
Heap:

Picture a large, shared storage space. This is where objects and their data reside. When you create an object using new, it's allocated space in the heap.
The heap is used for long-lived data like objects and arrays. It's slower to access but has more space. Think of it as a permanent storage area for your program's data.
The heap is shared by all threads in your program.
Key Differences:

Feature Stack Heap
Purpose Short-lived data (function calls) Long-lived data (objects, arrays)
Access Speed Faster Slower
Memory Allocation Automatic (with function call) Manual (using new)
Size Limited Large and dynamic
Thread Scope Private (per thread) Shared (by all threads)
Garbage Collection:

The heap needs to be managed efficiently to avoid memory leaks. Java uses a garbage collector that automatically identifies and removes unused objects from the heap.

Understanding Stack and Heap is Crucial:

Knowing where data is stored helps you optimize your code performance.
Stack overflows can occur if you have too many nested function calls.
Heap memory management is important to avoid memory leaks.