A must know checklist before any Frontend interview:

Javascript

  • Closures and its uses?
  • Function Scope vs Block Scope
  • Function Hoisting
  • Promises, Async/await vs Callbacks, Advantages?
  • Is JS Object Oriented? Comment.
  • Event Loop in JS.
  • Which prints first? Why? console.log("Hello World!") or setTimeout(()=>console.log("Hello World!"),0)
  • let vs var
  • type casting in Javascript, why every variable is a string by default?
  • Why everything can be reduced to Objects?
  • Meaning of __proto__, Prototypical Inheritance
  • ES6 Classes vs Writing Functional classes
  • this in JS
  • Implementing your own call, bind, apply
  • Immutability, spread operators

HTML/CSS

  • Box Model in CSS
  • Flexbox Model
  • Grid Model
  • What to use where ? Position: absolute, relative, fixed, static
  • Centering Elements in a div
  • Inline vs Block elements
  • What is Semantic HTML? Accessible Websites (Lost an internship because of this! :/)
  • Floats and its uses
  • async/defer in script tag
  • SASS Advantages
  • Critical Rendering Path

React/Redux

  • Component Life Cycle Methods
  • HOCs, Mixins, Functional Components vs Class Components
  • Hooks,
  • Why is React faster than normal DOM manipulation?
  • Redux usage and advantages
  • Major differences between angular and react
  • How does the diffing work
  • connect in Redux
  • Redux vs Flux
  • Redux pattern
  • Why do you need a state management library?
  • Implement your own Router, Redux
  • Flux and what is the difference between Flux and Redux?