Is there a functional way to init an array in JavaScript ES6?

Array.from() is a nice way to do this. You can pass a {length: somlength} object or some other array-like object and a function that defines each item. The first argument (calling it _ just to indicate it’s not used) to that function would be the item from an array we passed in (but we only passed in a length so it doesn’t mean much), the second i is the index, which is used for your id:

let sampleData = Array.from({length: 10}, (_, id) => ({id}))

console.log(sampleData)