Ever wondered how JavaScript, one of the most popular programming language, works under the hood? 🤔
JavaScript is single-threaded, meaning it executes one task at a time (think of it like a stack), line by line. 🕰️ But don't worry, this is actually a strength! Because it avoids the complexity of managing multiple threads, it reduces the risk of bugs like race conditions and deadlocks.
JavaScript has two main phases of execution: the memory creation phase and the code execution phase.
Memory Creation Phase: Before running your code, JavaScript first scans it to set up memory for variables and functions. This is called "hoisting," where declarations are moved to the top of their scope.
Note: If you want to see this, simply create a .js file with some lines of code where you declare variables and functions. Then, open the developer console and move to application (code section) put a debugger at the beginning of your script. Then re-run the code, go in scope tab you'll see how JavaScript sets up memory for these declarations before executing the code.
Code Execution Phase: Once memory is set up, JavaScript executes the code line by line. Functions and variables are assigned their values, and the code runs.
Despite being single-threaded, JavaScript handles multiple tasks at once using an event loop. This loop manages asynchronous tasks like network requests or timers, ensuring the main thread remains free to keep your web app responsive and smooth. 🚀
Next time you code in JavaScript, remember its single-threaded nature is a powerful feature. Embrace it to create amazing user experiences! 💻✨
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