The "this" keyword refers to the current execution context and is used to access object properties and methods within that context. It allows dynamic binding and enables flexible code reuse in object-oriented programming. The value of "this" depends on how a function is called or how an object is accessed.
Closures are a combination of functions and the lexical environment within which they were declared. They allow functions to retain access to variables from their parent scopes even after the parent function has finished executing. Closures are commonly used to create private variables, implement data encapsulation, and enable higher-order functions.
"let" and "const" are block-scoped variables introduced in ES6, while "var" is function-scoped. "let" and "const" variables have block-level scope, meaning they are limited to the block of code they are defined in, while "var" variables are hoisted to the top of their scope. "const" variables cannot be reassigned once defined, whereas "let" and "var" variables can be reassigned.
The candidate should mention using techniques like callbacks, Promises, or async/await. They should explain how they would structure their code to handle asynchronous operations, handle errors, and ensure proper sequencing or parallelism.
The candidate should discuss techniques like minimizing DOM manipulation, optimizing loops, reducing unnecessary computations, using efficient data structures, implementing caching mechanisms, leveraging web workers or service workers for background tasks, and utilizing performance profiling tools.
The candidate should mention steps like identifying the root cause of the bug, creating a minimal reproducible test case, fixing the issue with proper testing and validation, coordinating with other team members or stakeholders, deploying the fix, and implementing preventive measures to avoid similar issues in the future.
The candidate should mention strategies like using feature detection instead of browser detection, implementing polyfills or shims for missing functionalities, utilizing CSS frameworks or libraries that handle cross-browser compatibility, and testing the application on different browsers and versions.
The candidate should explain their approach to debugging, including techniques like using browser developer tools, console logging, setting breakpoints, analyzing stack traces and error messages, utilizing debugging extensions or tools, and implementing unit tests or integration tests.
The candidate should share an experience where they collaborated with team members, participated in code reviews, provided constructive feedback, communicated effectively, and adapted to team processes and requirements. They should highlight their teamwork and communication skills.
The candidate should provide an example where they had to communicate technical concepts to non-technical stakeholders. They should explain how they simplified complex ideas, used analogies or visual aids, and adapted their communication style to ensure clear understanding and alignment with stakeholders' expectations.