JavaScript Coding Interview Preparation Guide
Prepare for JavaScript coding interviews with common patterns and problems.
Common Topics
- Array manipulation (map, filter, reduce) - String operations - Object/Hash tables - Recursion - Big O notation - Closures and scope
Example: Two Sum
Find two numbers that add up to target:
function twoSum(nums, target) {
const map = new Map();
for (let i = 0; i < nums.length; i++) {
const complement = target - nums[i];
if (map.has(complement)) {
return [map.get(complement), i];
}
map.set(nums[i], i);
}
}
Example: Palindrome
Check if string is palindrome:
function isPalindrome(str) {
const clean = str.toLowerCase().replace(/[^a-z0-9]/g, '');
return clean === clean.split('').reverse().join('');
}
Interview Tips
- Think out loud - Ask clarifying questions - Start with brute force, then optimize - Test your solution with examples - Consider edge cases
Practice Resources
- LeetCode - HackerRank - CodeSignal - JavaScript.ac problems section