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Frontend Interview Questions

Prepare for your interview with our collection of relevant questions with probability indicators

📊 Total questions: 228 🔍 Found: 228

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What is algorithm complexity?

🟠 May come up 🎚️ Medium
🏷️ Algorithms

What is the difference between async and defer in JavaScript?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🌳 DOM 🚀 Performance

What browser storage options do you know? Tell about their differences.

🟢 Almost certain 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

Can an arrow function be used as a constructor? Why?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

Can React be used without JSX? How?

🟠 May come up 🎚️ Medium
⚛️ React

How to choose the right framework?

🟠 May come up 🎚️ Hard
🏷️ Architecture 🏷️ Frameworks 🟨 JavaScript

What is CI/CD?

🟡 Often asked 🎚️ Medium
🏷️ DevOps 🏷️ CI/CD 🏷️ Automation

What vulnerabilities exist?

🟠 May come up 🎚️ Medium
🛡️ Security

What are controlled and uncontrolled components in React?

🟠 May come up 🎚️ Medium
⚛️ React

How do CSS floats work?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML

What methods of style isolation exist?

🟡 Often asked 🎚️ Medium
🎨 CSS ⚛️ React 📄 HTML

How does browser load styles?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML 🏷️ Browser

What position property values do you know? What's the difference between them?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML

What does the word specificity mean in CSS?

🟡 Often asked 🎚️ Medium
🎨 CSS 📄 HTML

What is the difference between calling a function with call, apply, and bind?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is the difference between an Element and a Component?

🟠 May come up 🎚️ Medium
⚛️ React

What's the difference between iterating with for...of and for...in over an array?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What is the difference between Function Declaration and Function Expression?

🟡 Often asked 🎚️ Easy
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is the difference between functional and class components?

🟡 Often asked 🎚️ Medium
⚛️ React

What is the difference between in and hasOwnProperty()?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is the difference between a library and a framework using React as an example?

🟠 May come up 🎚️ Medium
⚛️ React

What's the difference between localStorage and sessionStorage?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

What's the difference between Map and WeakMap?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

What is the difference between an object and an array?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🏷️ Arrays 🟨 JS Basics

What is the difference between __proto__ and prototype?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is the difference between a regular function and a constructor function?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What's the difference between Set and WeakSet?

🟠 May come up 🎚️ Hard
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

What is the difference between Shadow DOM and Virtual DOM?

🟠 May come up 🎚️ Medium
⚛️ React

What is the difference between shallow and deep copying of an object?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What's the difference between splice and slice methods?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What is the difference between synchronous and asynchronous functions?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⚙️ Functions ⏱️ Asynchronicity 🟨 JS Basics

What is the difference between useEffect and useLayoutEffect?

🟡 Often asked 🎚️ Medium
⚛️ React 🏷️ Hooks

Do var and let work the same inside a function?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is DOM?

🟠 May come up 🎚️ Medium
🟨 JavaScript 📄 HTML 🏷️ Browser

What ES6 features are you familiar with?

🟡 Often asked 🎚️ Medium
🟨 JavaScript

What’s the difference between event.preventDefault and event.stopPropagation?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🌳 DOM ⚡ Events

What is the difference between Grid and Flex?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML

What are the ways to hide an element?

🟠 May come up 🎚️ Easy
🎨 CSS 📄 HTML ⚛️ React

What are Higher-Order Components (HOCs)?

🟠 May come up 🎚️ Medium
⚛️ React

How does the at method work? How is it different from direct indexing?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How does the HttpOnly attribute work with cookies?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

How does prototypal inheritance work?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How does React reconciliation work?

🟡 Often asked 🎚️ Medium
⚛️ React

How does the rest parameter (...args) work in functions?

🟡 Often asked 🎚️ Easy
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

How to add a new property to an object?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to avoid race condition?

🟠 May come up 🎚️ Hard
🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

How to cancel an asynchronous operation? (AbortController)

🟠 May come up 🎚️ Medium
🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

How to change the value of a property in an object?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to check if a property exists in an object?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to clone an object? assign, spread operator, JSON.parse(JSON.stringify), Object.create, recursive traversal, structuredClone.

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How are objects compared with == or ===?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to copy an array?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How to create a Promise?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

How to delete Cookies?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

How to delete a property from an object?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to find unique values in an array?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How to iterate all object properties with for...in loop?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to iterate object values with Object.values()?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

How to merge two arrays?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How to prevent unnecessary renders in React?

🟡 Often asked 🎚️ Medium
⚛️ React

How to remove an element from an array? Name different ways.

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How to implement retry of an asynchronous operation on error?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⏱️ Asynchronicity

How to set the default value of a function?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🟨 JS Basics ⚙️ Functions

How to sort an array of numbers correctly?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

Tell me how you use git and what main commands you use?

🟠 May come up 🎚️ Medium
🏷️ Git

What are response codes and how do they differ from each other?

🟡 Often asked 🎚️ Medium
🏷️ HTTP 🏷️ API 🏷️ Web

What is the difference between HTTP and HTTPS?

🟠 May come up 🎚️ Medium
🏷️ Web 🏷️ HTTP

Why is HTTPS needed everywhere?

🟠 May come up 🎚️ Medium
🏷️ Web 🏷️ HTTP

How to communicate between iframe and the page?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🛡️ Security

Is console.log() a Side Effect?

🟠 May come up 🎚️ Hard
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

How to check if it's an array?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

How to quickly clear an array?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What array creation methods do you know?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What array methods do you know?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What is an array and how to work with it?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

What are arrow functions and what are their differences?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

Give examples of binary operators in JavaScript and what are their differences?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics 🏷️ Operators

What is a closure in JavaScript and how does it work?

🟡 Often asked 🎚️ Hard
🟨 JavaScript 🟨 JS Basics

What data types exist in JavaScript?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics

What is the difference between == and === in JavaScript and when is it better to use which operator?

🟢 Almost certain 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Operators

What function declaration methods do you know and what are their differences?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What can you pass to a function as a parameter?

🟡 Often asked 🎚️ Easy
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What are functions for in JavaScript and what problems do they solve?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics ⚙️ Functions

What is hoisting in JavaScript?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics 🏷️ Data types

What are self-invoking functions and why are they needed?

🟠 May come up 🎚️ Hard
🟨 JavaScript ⚙️ Functions

What is the difference between i++ and ++i in JavaScript and what do they return?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Operators

Have you heard about the nullish coalescing operator (??) ? Can you tell me about it?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Operators

How to convert a value to number in JavaScript?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics 🏷️ Data Types

What can be object keys and values in JavaScript?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What methods does an object have in JavaScript?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is a pure function in JavaScript?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics ⚙️ Functions

How to convert a value to string in JavaScript?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics 🏷️ Strings

What string methods do you know?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Strings 🟨 JS Basics

How does the switch operator work in JavaScript and how does comparison happen?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Conditional

What is the ternary operator and how does it work in JavaScript?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Conditional

What does the typeof operator do and in what format does it return data?

🔴 Rarely asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics

What are the different ways to declare variables in JavaScript and what are their differences?

🟢 Almost certain 🎚️ Easy
🟨 JavaScript 🟨 JS Basics 🏷️ Data Types

What are the KISS, DRY, and YAGNI principles in development?

🟠 May come up 🎚️ Medium
🏷️ Programming Principles

What are macro and micro tasks?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Event Loop ⏱️ Asynchronicity

Map. What's special about it? What properties and methods does it have? How to iterate?

🟡 Often asked 🎚️ Hard
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

What is Nginx? Have you worked with it?

🟠 May come up 🎚️ Medium
🏷️ Web 🏷️ HTTP

What's the difference between null and undefined?

🟡 Often asked 🎚️ Easy
🟨 JavaScript 🟨 JS Basics

What is Object.freeze() and how is it different from Object.seal()?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What do Object.keys/Object.values/Object.entries do with an array?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Arrays 🏷️ Objects 🟨 JS Basics

What are the peculiarities of object storage?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is prop drilling?

🟠 May come up 🎚️ Easy
⚛️ React

What are the pros and cons of using React?

🟠 May come up 🎚️ Medium
⚛️ React

What pseudo-classes are there?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML

What is a pseudo-element?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML

Do you have any questions for us?

🟢 Almost certain 🎚️ Hard
🌱 soft-skills

What's new in React 19?

🟠 May come up 🎚️ Medium
⚛️ React

What are React Developer Tools?

🟠 May come up 🎚️ Easy
⚛️ React 🏷️ DevTools

How to handle events in React?

🟠 May come up 🎚️ Medium
⚛️ React

What is the difference between render phase and commit phase in React Fiber?

🟠 May come up 🎚️ Hard
⚛️ React

What is forwardRef and why is it needed?

🟠 May come up 🎚️ Medium
⚛️ React

What attributes can React Fragment accept?

🟠 May come up 🎚️ Easy
⚛️ React

What is React.lazy() and what is it used for?

🟡 Often asked 🎚️ Hard
⚛️ React

How to properly use React.lazy() with Suspense?

🟡 Often asked 🎚️ Hard
⚛️ React

What are the ways to optimize a React application?

🟡 Often asked 🎚️ Medium
⚛️ React

How to work with query parameters in React?

🟠 May come up 🎚️ Easy
⚛️ React

What is React Router?

🟠 May come up 🎚️ Medium
⚛️ React

What are React Server Components (RSC)?

🟠 May come up 🎚️ Hard
⚛️ React 🟨 Next.js 🏷️ SSR

What is Strict Mode in React? Why is it needed?

🟠 May come up 🎚️ Medium
⚛️ React

What are the alternatives to Redux?

🟡 Often asked 🎚️ Medium
⚛️ React 🏷️ State Management

What is a relative link?

🟠 May come up 🎚️ Easy
📄 HTML 🏷️ URL

Why do we need Reset.css?

🟠 May come up 🎚️ Medium
🎨 CSS 📄 HTML 🏷️ Browser

What is the difference between REST and RESTful API?

🟡 Often asked 🎚️ Medium
🏷️ API 🏷️ REST 🏷️ Backend

What are the risks of storing tokens in cookies?

🟠 May come up 🎚️ Hard
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

What are your salary expectations?

🟢 Almost certain 🎚️ Hard
🌱 soft-skills

Set. What's special about it? What properties and methods does it have? How to iterate?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

What to do and avoid in website optimization?

🟠 May come up 🎚️ Medium
🚀 Performance 🏷️ Optimization 🏷️ Web

What’s the difference between SOAP and REST?

🟠 May come up 🎚️ Medium
🏷️ API 🏷️ HTTP 🏷️ Architecture

What are SPA applications?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⚛️ React 🏷️ SPA

What is SSR?

🟠 May come up 🎚️ Medium
⚛️ React 🟨 Next.js 🏷️ SSR

What is TDD?

🟠 May come up 🎚️ Medium
🏷️ Testing 🏷️ TDD 🟨 JavaScript

Tell me about yourself

🟢 Almost certain 🎚️ Hard
🌱 soft-skills

What are the top 10 libraries you've used when building React applications?

🟠 May come up 🎚️ Medium
⚛️ React

How does toString work?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Type Coercion 🏷️ String

What does useCallback do and how does it differ from useMemo?

🟡 Often asked 🎚️ Medium
⚛️ React 🏷️ Hooks

What is the useFormState hook?

🟠 May come up 🎚️ Medium
⚛️ React 🏷️ Hooks

What is the difference between useRef and createRef?

🟠 May come up 🎚️ Medium
⚛️ React 🏷️ Hooks

WeakMap. What's special about it? What properties and methods does it have? How to iterate?

🟠 May come up 🎚️ Hard
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

WeakSet. What's special about it? What properties and methods does it have? How to iterate?

🟠 May come up 🎚️ Hard
🟨 JavaScript 🏷️ Collections 🟨 JS Basics

What architectural patterns do you know, and what are their features?

🟠 May come up 🎚️ Hard
🏷️ Theory

What are controlled and uncontrolled components?

🟠 May come up 🎚️ Medium
⚛️ React

What are Cookies? Tell what they're for and how you used them.

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

What design patterns do you know, and what are their features?

🟠 May come up 🎚️ Hard
🏷️ Theory

What properties does an error object have?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics

What are the principles of Functional Programming?

🟠 May come up 🎚️ Hard
🏷️ FP 🏷️ Theory

What are fragments (<>...</>)? Why is it better to use fragment instead of an extra div?

🟠 May come up 🎚️ Medium
⚛️ React

What are generators and how are they related to asynchronicity?

🟠 May come up 🎚️ Hard
🟨 JavaScript ⏱️ Asynchronicity

What is the key in lists for? What will happen if you use an array index as a key?

🟡 Often asked 🎚️ Medium
⚛️ React

What types of loops in JavaScript do you know, and what are their differences?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Loops 🟨 JS Basics

What are the principles of OOP?

🟠 May come up 🎚️ Hard
🏷️ OOP 🏷️ Theory

What are portals (Portals) in React?

🟠 May come up 🎚️ Medium
⚛️ React 🏷️ Portals

What are props and why are props immutable?

🟠 May come up 🎚️ Medium
⚛️ React

What are "pure" components (Pure Components)?

🟠 May come up 🎚️ Medium
⚛️ React

What are spread and rest operators?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🟨 JS Basics 🏷️ Objects 🏷️ Arrays

What are Synthetic Events in React?

🟠 May come up 🎚️ Medium
⚛️ React

Describe the main phases of the React component lifecycle and the corresponding methods for class and functional components

🟢 Almost certain 🎚️ Hard
⚛️ React

What are the rules for using hooks in React?

🟡 Often asked 🎚️ Medium
⚛️ React 🏷️ Hooks

What are third-party cookies? Why do browsers block third-party cookies?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

What are Web Workers and how are they related to asynchronicity?

🟠 May come up 🎚️ Hard
🟨 JavaScript ⏱️ Asynchronicity

What are the main factors that cause React components to re-render?

🟡 Often asked 🎚️ Medium
⚛️ React

What data type is a function?

🔴 Rarely asked 🎚️ Easy
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What do .then(), .catch(), .finally() methods return?

🟡 Often asked 🎚️ Medium
🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What does the async keyword do?

🟠 May come up 🎚️ Medium
🟨 JavaScript ⚙️ Functions ⏱️ Asynchronicity 🟨 JS Basics

What does the hasOwnProperty() method do?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What does the in operator do for objects?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What does the JSON.stringify() method do to an object?

🟡 Often asked 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What does Object.entries() return and what is it used for?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What does useEffect do? When does an effect without dependencies trigger? What is the dependency array for?

🟢 Almost certain 🎚️ Easy
⚛️ React 🏷️ Hooks

What does accessing a non-existent property return?

🟠 May come up 🎚️ Easy
🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What happens when localStorage limit is exceeded?

🟠 May come up 🎚️ Medium
🟨 JavaScript 🏷️ Browser 🟨 JS Basics

What happens after we enter a URL in the browser bar?

🟠 May come up 🎚️ Hard
🏷️ Theory

What is an anonymous function?

🟠 May come up 🎚️ Easy
🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is async/await?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is asynchronous code execution?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is await and how does it work?

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🟨 JavaScript ⚙️ Functions ⏱️ Asynchronicity 🟨 JS Basics

What is a callback and how is it used?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is conditional rendering in React?

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⚛️ React 🏷️ Rendering

What is a constructor function?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is CORS?

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🏷️ Browser

What is currying?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is destructuring and how does it work?

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🟨 JavaScript 🟨 JS Basics 🏷️ Arrays 🏷️ Objects

What is Event Loop?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is a function execution context?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is hoisting and how does it affect functions?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is JSX and why is it needed?

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⚛️ React

What is a Map object and how is it different from a regular object?

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🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is NaN, what is its type, and how to check for it?

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🟨 JavaScript 🏷️ Data Types 🟨 JS Basics

What is an object?

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🟨 JavaScript 🟨 JS Basics 🏷️ Objects

What is Object.keys() used for?

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🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is Promise.all() used for

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is Promise and why is it needed?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is Promise.any() for?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is Promise.race() for?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is promisification?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is a prototype chain?

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🟨 JavaScript 🏷️ Objects 🟨 JS Basics

What is React and what problems does it solve?

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⚛️ React

What is React Fiber? What is the main goal of React Fiber?

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⚛️ React

What is React.memo, how does it work, where is it applied and for what purpose?

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⚛️ React

What is recursion? Give an example.

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is setInterval, what is it for, and how does it work?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is setTimeout, what is it for, and how does it work?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

What is «state lifting» in React?

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⚛️ React

What is the Temporal Dead Zone (TDZ)?

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🟨 JavaScript 🟨 JS Basics

What is the this keyword used for inside a function?

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🟨 JavaScript ⚙️ Functions 🟨 JS Basics

What is the throw operator for?

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🟨 JavaScript 🟨 JS Basics

What is try...catch for?

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🟨 JavaScript ⏱️ Asynchronicity 🟨 JS Basics

Tell us about the useCallback hook, how it works, where it's applied and for what purpose?

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⚛️ React 🏷️ Hooks

Tell us about the useContext hook, how it works, where it's applied and for what purpose? When is it better to use it, and when is it better to refuse?

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⚛️ React 🏷️ Hooks

Tell us about the useId hook, how it works, where it's applied and for what purpose?

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⚛️ React 🏷️ Hooks

Tell us about the useMemo hook, how it works, where it's applied and for what purpose?

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⚛️ React 🏷️ Hooks

Tell us about the useOptimistic hook, how it works, where it's applied and for what purpose?

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⚛️ React 🏷️ Hooks

Tell us about the useRef hook, how it works, where it is used and what for?

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⚛️ React 🏷️ Hooks

Tell us about the useState, how does it work, where is it applied and what is it for?

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⚛️ React 🏷️ Hooks

Tell us about the useTransition hook, how it works, where it's applied and for what purpose?

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⚛️ React 🏷️ Hooks

What is Virtual DOM?

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⚛️ React

What React Hooks do you know?

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⚛️ React 🏷️ Hooks

When is it appropriate to use class components today?

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⚛️ React

Which array methods mutate and which don't?

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🟨 JavaScript 🏷️ Arrays 🟨 JS Basics

Why are you changing jobs?

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🌱 soft-skills

Why can you modify fields of an object declared with const?

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🟨 JavaScript 🏷️ Objects 🟨 JS Basics

Why use Docker?

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🏷️ DevOps 🏷️ Backend

Why hooks appeared and what did they replace?

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⚛️ React 🏷️ Hooks

Why should you pass a function to setState()?

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⚛️ React ⏱️ Asynchronicity

Tell me about your work processes

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🌱 soft-skills