When it comes to memory selection for your program, the question of stack vs. heap arises.
Because they both have the Last in First out (LIFO) principle to handle their insertion and deletion operations, as a result, people get confused about their difference, and making a choice between them is difficult.
This article will guide you about every single thing you want to know about stack and heap.
Table of Contents
What is Stack?
Stack is a temporary memory used during the program; once completed, it is erased from the memory.
The stack consists of the Last in First out (LIFO) principle. Stack has a linear data structure that means it stores elements in a linear format.
Operations in Stack
The two main operations in Stack are push and pop. Push operation is used to add an element to a Stack. Pop operation is used to remove an element to Stack.
All the operations in Stack are done at the top of the Stack. If you want to add an element by push operation, the element is added here at the top, and the top value increases by 1.
Similarly, when an element is removed from the Stack, the top value is decreased by 1. The top pointer of the stack is called the Stack pointer. There are some other operations in Stack:
- Peek: Show the topmost element
- Duplicate: Copy the topmost element and push it back in the Stack
- Swap: Swap the two topmost elements.
- Rotate: Move topmost elements in a rotating movement.
Advantages and disadvantages in stack
|it manages the data in LIFO format.||It is limited.|
|It cannot easily ruin.||It does not support random access.|
|It helps the user to choose the allocation and deallocation of memory.||It is not flexible.|
|The local variables are store in the stack when a function is called.||It has low scalability.|
|It automatically cleans the objects.|
|It cannot be easily corrupt.|
|It does not allow the resizing of variables.|
What is heap?
Programmers use the heap to store global variables. Heap is a hierarchical data structure. It is based on a tree structure format.
Heap stores data in root to tip form. Each element in Heap is store in a node. Datastore in Heap in like a family tree. The relation between the nodes of a tree is parent-child, sister nodes, etc.
There are two types of Heap.
Max Heap: The value of the root node is greater than or equals to its child node.
Min Heap: The value of the root node is less than or equals to its child node.
Operations in Heap:
Following are the common operations in Heap:
- Insert: it inserts a node in the Heap.
- Delete: it deletes a node from the Heap.
- Find-max: It finds the maximum item from the max-heap.
- Find-min It finds the minimum item from the min-heap.
Advantages and disadvantages of heap:
|It has an unlimited memory size.||It takes time to process.|
|It can easily find the greatest and lowest number in the memory.||Its memory limit depends on the memory limit of the OS.|
|It drains the unrequired collection in the memory.||It has a complicated memory management system.|
|It has the ability to use the graph algorithm efficiently.||It has a slow speed.|
|Heap is based on a priority queue.|
|It is very flexible.|
Stack vs heap
|Stack is used for static memory allocation.||Whereas heap is used for dynamic memory allocation.|
|The data structure of the stack is linear.||The data structure of the heap is hierarchical.|
|Stack has high access speed faster access time.||Heap has a slower access speed and time.|
|Stack only access local variables.||While heap allows accessing variables globally.|
|Stack is cheaper.||Heap is expensive than the stack.|
|The stack can be implemented in 3 ways, array, linked list, and dynamic memory.||While heap can be implemented with array and trees.|
|The allocation and deallocation in the stack are done automatically by the compiler.||While in a heap, it is manually done by the programmer.|
|The resizing of variables cannot be allowed in the stack||While heap allows the resizing|
|In stack, the space is managed efficiently by the OS, so the memory will never break.||While heap does not manage space efficiently hence, it results in memory fragments.|
|Stack size is limited and depends upon the OS.||Heap does not have a limited memory size.|
|In the stack, memory is assigned in adjacent blocks.||While in a heap, it is allocated randomly.|
|The main issue in the stack is the storage of memory.||The main issue in a heap is memory fragmentation.|
|It is not flexible as it has a fixed size.||It is very flexible because it can be resized.|
|Stack does not need to be deallocated.||Heap needs to be deallocated.|
Stack vs Heap – in terms of data structure:
Stack is a linear type data structure. At the same time, a heap is a hierarchical form based on the tree-structured data type.
Stack only access local variables. At the same time, the heap can access global variables.
Resizing variables in the stack is possible. However, it is impossible to resize variables in a heap.
Stack vs. heap – in terms of memory:
Stack is used for static memory allocation. At the same time, the heap is used for dynamic memory allocation.
In the stack, memory is assigned in adjacent blocks, whereas heap memory allocates randomly.
Storage of memory is the main issue in the stack. However, memory fragmentation is the real concern issue in a heap.
Stack vs. heap – in terms of speed:
In stack, the absolute virtual address and the relative address can be calculated at compile-time, so the access speed for stack-based data is breakneck.
The data is in heap access during the runtime. This data contains the virtual memory address. This may take a longer time to access.
When to use stack and Heap:
If you want a large amount of memory to allocate the blocks, the heap is a good option. But if you are working with relatively small variables, then the stack is a better option.
Stack is used to access the local variables with temporary storage of memory.
The final answer on the debate of stack vs. heap states that both stack and heap are based on the Last in First out (LIFO) principle. However, the stack is a linear data structure that means it stores data in a sequence.
Heap is used to accessing global variables with a tree-structured memory.
Heap has a tree structure form, which means heap store data in hierarchical form. Each element in a heap is store in the form of nodes.
If you want a large amount of memory to allocate the blocks, then heap is a good option. But if you are working with relatively small variables, then the stack is a better option.
To understand more about Stack and Heap memories with their advantages and disadvantages, read the complete article.
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