Use Number to convert string to numbers in a copy of an array after using slice and spread operator

Question

I wasn't able to find an exact solution or if it is even possible. I have an example array and I wont be using the first two values, and I wanted to transform those strings to numbers with Number() and using the spread operator to convert each value in one go.

let array = ['1','2','3','4','5','6']
let result = Number(...array.splice(2));

the result of this is 3 is there a way to use the spread operator? or the only way out of this is to use map.

The expected result is result = [3,4,5,6] so only numbers. The array of strings is just an example, it might have more strings inside or less.

Answer 1

The Number constructor converts one value to a number - Number(value)

You're putting in as value a spreaded array from which the first value is taken and converted

Number(...array.splice(2))  // Number('3','4','5','6') => 3

I don't see any good example using the spread operator, since you don't want to get rid of the array structure, but have to iterate the array for converting each element from string to number

1. For getting rid of the first two entries without altering the original array use .slice() The second argument can be omitted if you want to slice from the index to the end of the array
2. To keep it short you can directly map on the spliced array using either the Number(v) constructor or by simply adding the + at the front

let array = ['1','2','3','4','5','6']
let numbers1 = array.slice(2).map(str => +str) // [3, 4, 5, 6]
let numbers2 = array.slice(2).map(str => Number(str)) // [3, 4, 5, 6]