JavaScript Functions, Scope and Closures Explained for Interview Prep

A technical guide aimed at JavaScript developers covers key interview topics including closures, lexical scoping, and function hoisting. Closures occur when an inner function retains access to variables from its outer function's scope even after that outer function has finished executing, enabling patterns like data privacy, factory functions, and memoization. Lexical scoping means a variable's accessibility is determined by where it is written in source code, not by runtime call order, making closure behavior consistent and predictable. Function declarations are fully hoisted by the JavaScript engine, allowing them to be called before they appear in the code, while function expressions are not assigned until their line executes. The article is the second installment in an ongoing JavaScript interview preparation series, with the first part covering fundamentals and data types.