Summing arrays of numbers is fundamental for calculating totals, statistical analysis, financial computations, and implementing features like shopping cart totals or data aggregation in JavaScript applications. With over 25 years of experience in software development and as the creator of CoreUI, I’ve implemented array summation in components like data tables, chart calculations, and financial widgets where accurate total calculations are essential for user interfaces and business logic. From my extensive expertise, the most elegant and functional approach is using the reduce() method with an accumulator. This method is concise, readable, and follows functional programming principles while handling empty arrays gracefully.