JavaScript – Is Set better than Array?

What are differences between Set and Array?

• Arrays can have duplicate values but Sets can’t
• Array is ordered by index. Set uses keys and elements are iterable in the order of insertion

When is Set better than Array?

Removing duplicate items

let aSet = new Set(anArray);        // ['A', 'B', 'B', 'C', 'D', 'B', 'C'] => {"A", "B", "C", "D"}

let aSet = [...new Set(anArray)];   // ['A', 'B', 'B', 'C', 'D', 'B', 'C'] => ["A", "B", "C", "D"]