how to use spread syntax and new Set with TypeScript

Question

I am using following code to get unique numbers:

let uniques = [ ...new Set([1, 2, 3, 1, 1]) ]; // [1, 2, 3]

However, typescript report following error: Type 'Set' is not an array type. I am not typescript ninja, could someone tell me what is wrong here?

Answer 1

The ... operator should work on anything that has an iterator property, (Accessed by obj[Symbol.iterator]) and Sets have that property.

To work around this, you can use Array.from to convert the set to an array first: ...Array.from(new Set([1, 2, 3, 1, 1])).