A LIFO (Last In, First Out) stack that tracks the currently executing functions. javascript

| Topic | Must-Have Questions | |-------|----------------------| | | Counter module, event loop + closure pitfalls | | Hoisting | var / let / const + temporal dead zone | | Promises & Async | async/await vs promises, promise polyfill | | Prototypes & Inheritance | __proto__ , Object.create , ES6 classes | | Map / Set / WeakMap | Use cases, memory differences | | Event Loop | Output questions with setTimeout , promises, microtask queue | | ES2020–ES2024 | Optional chaining, nullish coalescing, Array.groupBy , structuredClone, toSorted |

The TDZ is the behavior in JavaScript where variable declarations using let and const are hoisted but not initialized. It begins at the start of the block scope. It ends when the engine evaluates the variable declaration.

This comprehensive guide compiles essential JavaScript interview preparation concepts inspired by popular community resources like Happy Rawat's study guides. Use this breakdown to ace your next technical screening. 1. Core JavaScript Fundamentals

function first() console.log('First'); second(); function second() console.log('Second'); first(); // Execution order in stack: Global -> first() -> second() Use code with caution.

: Highlighting arrow functions, destructuring, rest/spread operators, and classes. Asynchronous JavaScript : Extensive coverage of Promises, async/await , and callback functions. Tricky Questions

Explain its behavior in global scope, objects, arrow functions, and event listeners.

Describe the Event Loop.The Event Loop manages the execution of multiple chunks of code. It monitors the Call Stack and the Callback Queue.

Unlike class-based languages like Java or C++, JavaScript uses prototypal inheritance. Every JavaScript object has an internal property called [[Prototype]] (accessible via __proto__ or Object.getPrototypeOf() ) that links it to another object. If a property is not found on the object itself, JavaScript searches up the prototype chain until it finds it or hits null . Explicit Binding: Call, Apply, and Bind