This project implements a solution to the classic Cracking the Coding Interview problem “Is Unique”. The goal is to determine whether a given string contains all unique characters. I used JavaScript to create a function isUnique(str) that returns true if every character in the string is unique, and false if any character repeats. I tested the solution with a few examples, such as “abcde” returning true and “abcdea” returning false. This project gave me practice in working with sets, loops, and string manipulation in JavaScript. It also helped me think about algorithmic efficiency, since different approaches (hash set, sorting, brute force) offer trade-offs in time and space complexity.