JavaScript Execution Context – How JS Works Behind The Scenes

In JavaScript, understanding the concept of execution context is crucial to grasp how the language works behind the scenes. When JavaScript code is run, it operates within an execution context that consists of variables, functions, and the scope chain. The global execution context is the default context where code begins its execution.

As code is executed, JavaScript creates new execution contexts for functions invoked during runtime. These function execution contexts are added to the top of the execution stack, forming a stack known as the “call stack.” Each execution context has its own variable environment, scope, and reference to its outer lexical environment.

The process of managing execution contexts and the call stack is fundamental to how JavaScript manages function calls, variable scope, and closures. By understanding how JavaScript handles execution contexts behind the scenes, developers can write more efficient and reliable code that takes advantage of JavaScript’s scoping rules and function invocation processes.