How JavaScript Works
Sonu Kumar
Frontend Engineer @ Wellness Extract | React.js & Next.js Expert | Vue.js | Angular | Node.js | React Router & Redux | React Query & GraphQL | PWA & SaaS Developer | 3+ Years Crafting Modern, Scalable Products
In JavaScript, everything revolves around the Execution Context. Think of the Execution Context as a "black box" where your code is executed. This context has two main components:
Before executing the code, JavaScript scans through the code and allocates memory for all declared variables and functions.
Variables are initially assigned the value undefined, while the entire function definition is stored in memory.
2. Code Component (Thread of Execution)
This is where JavaScript executes the code line by line, following the sequence of instructions.
3. Key Characteristics of JavaScript
Single-Threaded
JavaScript can only execute one task at a time in a single thread. This means it processes code sequentially, from top to bottom.
Synchronous
By default, JavaScript executes tasks one after the other, waiting for one task to finish before moving to the next.