A Complete Guide to Preparing for a JavaScript Interview (Without Losing Your Shit)

1. Understand the Fucking Battlefield

JavaScript interviews for beginners and intermediates are mostly about coding, trivia, and behavioral questions. Here’s the breakdown:

• Coding: Basic algorithms and utility functions (like debounce or deepClone).
• Trivia: JavaScript quirks, CSS/HTML basics, and “WTF is event bubbling?” moments.
• Behavioral: “Tell me about a time you fucked up” questions.

Pro Tip: Even if you’re intermediate, don’t skip fundamentals. Interviews love to ask about NaN === NaN just to watch you squirm.

2. JavaScript Fundamentals: The Non-Negotiables

Master these, or get ready to cry in the interview:

1. Data Types & Coercion
   • Why does "5" + 3 = "53" but "5" - 3 = 2? Because JavaScript hates you.
   • === vs ==? Use === unless you enjoy debugging type-related nightmares.
2. Scope & Hoisting
   • var is a relic. let and const are your new gods.
   • Why does console.log(x) return undefined if var x = 5 is below it? Hoisting, bitch.
3. Closures & this
   • Closures: When a function remembers its lexical scope (e.g., setTimeout inside a loop).
   • this changes based on how you call a function. Learn bind, call, and apply or suffer.
4. Promises & Async
   • If you use .then() without understanding the event loop, you’re gonna have a bad time.
   • Async/await is syntactic sugar, but it’s good sugar.

3. Coding Challenges: Grind, But Smart

Algorithms

• Focus on basic patterns, not memorizing LeetCode hard-mode bullshit:
  • Recursion: Fibonacci, factorial.
  • Array Manipulation: Filtering, mapping, reducing.
  • String Operations: Palindrome checks, reversing strings.

Utility Functions

• Build these from scratch:
  • debounce(): For search bars that shouldn’t spam APIs.
  • deepClone(): Because JSON.parse(JSON.stringify(obj)) is a hack, not a solution.

UI Building

• Practice simple components:
  • A modal that closes when clicking outside.
  • A dropdown menu that doesn’t break when you sneeze.

4. Behavioral Questions: Don’t Be a Robot

Interviewers want to know if you’re a human, not a code-generating NPC. Use the STAR method:

• Situation: “My team missed a deadline because…”
• Task: “I had to refactor the spaghetti code…”
• Action: “I implemented testing and…”
• Result: “We shipped it 2 weeks faster next time.”

Common Questions:

• “What’s your biggest weakness?” → “I refactor code obsessively. Yes, it’s a problem.”
• “Why do you want this job?” → Don’t say “for the money.”

5. Practical Prep: Stop Procrastinating

• Mock Interviews: Use Pramp or ask a friend to grill you.
• Tools:
  • freeCodeCamp or Codecademy: For hands-on JS basics.
  • Frontend Interview Handbook: Your bible for JS, HTML, CSS trivia.
• Stay Updated: Learn ES6+ features (arrow functions, destructuring).

Final Rant

Interviews are a game. Learn the rules, play smart, and don’t take rejection personally. Beginners get tripped up by typeof null === "object", intermediates forget how Array.reduce() works.

Now get the fuck out there and practice.

Resources (Beginners/Intermediate Edition)

1. Coding & Basics:
   • JavaScript Utility Functions
   • Building Simple UIs
2. Trivia & Core Concepts:
   • JavaScript Questions
   • CSS Questions
   • HTML Questions
3. Behavioral Prep:
   • Behavioral Interview Guide
4. General Prep:
   • Frontend Interview Handbook

Need more advice? The links above won’t let you down. Now go crush it (and maybe stop cursing so much).