What is the difference between stack and heap in JavaScript

Difference: 1. In memory operations, the stack is automatically allocated and released by the operating system, while the heap is allocated and released independently by the developer; 2. In the data structure, the stack is a linear operation-limited The table only allows insertion and deletion operations at one end of the table, while the heap is a priority queue that will execute the highest priority first according to the priority.

The operating environment of this tutorial: Windows 10 system, JavaScript version 1.8.5, Dell G3 computer.

What is the difference between stack and heap in JavaScript

When understanding the two concepts of heap and stack, you need to understand it in a specific scenario. Generally speaking, it has two meanings:

(1) In the memory operation scenario, heap and stack represent two memory management methods.

(2) In the data structure scenario, heap and stack represent two commonly used data structures.

1. Memory operation scenario

The stack is automatically allocated and released by the operating system and is used to store simple data segments, occupying a fixed size of space, such as basic data types (Number, String, Boolean...) and function parameter values, etc.

The heap is allocated and released by the developer independently. If it is not released actively, it will be recycled by the browser at the end of the program and is used to store reference types (variables of reference types actually save not the variable itself, but point to the memory space pointer).

Data types in JavaScript

2. Data structure scenarios

JavaScript has the concepts of stack and queue, and the stack is imitated through arrays.

Stack: The stack is a linear table with limited operations. The restriction means that only insertion and deletion operations are allowed at one end of the table. This end is called the top of the stack (Top). Relatively speaking, Call the other end the bottom of the stack. Putting a new element on top of the top element of the stack to make it a new top element is called pushing, pushing, or pushing; deleting the top element of the stack makes its adjacent elements become the new top of the stack. Elements are called pop or pop (Pop). The stack is implemented through the push() and pop() methods of the array.

Heap: The heap is actually a priority queue, which means that there is a priority in the queue. For example, if there are many tasks to be executed in the queue, the one with the highest priority will be executed first according to the priority.

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