Modern JavaScript Fundamentals Questions

Focuses on modern JavaScript language features, semantics, and runtime behavior used in frontend and general JavaScript development. Topics include ES2015 and newer syntax and constructs such as arrow functions, destructuring, spread and rest operators, template literals, let and const scoping, classes, and modules. Also include asynchronous programming patterns and runtime concepts such as Promises, async and await, the event loop, callback queue and microtask queue, closure, scope and hoisting, prototypal inheritance and the this keyword, and common browser concerns such as event handling, basic DOM manipulation, and interaction with browser APIs. Interviewers assess both conceptual understanding and practical usage, including debugging and choosing idiomatic patterns.