Dealing with duplicate values in JavaScript arrays is a common issue, especially when working with data from APIs or user input where duplicate entries can occur unexpectedly. With over 25 years of experience in software development and as the creator of CoreUI, I’ve solved this problem countless times in production components like user lists, tag systems, and data aggregation features where clean, unique datasets are essential. From my extensive expertise, the most efficient and modern solution is to use the ES6 Set object together with the spread operator. This method is concise, reliable, and supported across all modern browsers while maintaining excellent performance.