JavaScript is a single-threaded language, which means that it can only execute one piece of code at a time. This poses a problem when dealing with asynchronous operations like network requests, timers, and user input. The solution to this problem is the Event Loop.
The Event Loop is a mechanism that allows JavaScript to execute code in a non-blocking, asynchronous manner. It achieves this by maintaining a queue of tasks to be executed and constantly checking the queue for new events to execute.
Here’s how the Event Loop works in JavaScript:
The Call Stack
When a script is executed, JavaScript creates a Call Stack, which is a data structure that stores the context of the currently executing function. When a function is called, its context is pushed onto the Call Stack, and when the function returns, its context is popped off the stack.
Web APIs
Web APIs are JavaScript functions that are provided by the browser or the environment in which the code is running. Examples of Web APIs include timers, network requests, and the DOM API. When a Web API is called, it is executed outside of the JavaScript runtime, and a callback function is registered to be called when the operation is complete.
