let arrayOfStrings = ["1","2","3","4"]
let arrayOfNumbers = arrayOfStrings.map(Number)
console.log(arrayOfNumbers) // [1,2,3,4]
arrayOfStrings = arrayOfNumbers.map(String)
console.log(arrayOfStrings ) //["1","2","3","4"]
let arrayOfStrings = ["1","2","3","4"]
let arrayOfNumbers = arrayOfStrings.map(Number)
console.log(arrayOfNumbers) // [1,2,3,4]
arrayOfStrings = arrayOfNumbers.map(String)
console.log(arrayOfStrings ) //["1","2","3","4"]