How to check if item of string array can be converted to valid number?

Question

I have a string arrays like ['2022/10', '2021/05', '2022/01'], ['John','Olivia','Adam'], ['1.23','2.34','101'] in the same table. I want to convert those items of arrays to number but only if the item can be converted to number. For above example only ['1.23','2.34','101'] can be converted and other should be same. I tried to combine common methods like isNaN and parseFloat but couldn't manage. Because when I try to convert, it always gives NaN if the array can' be converted

Are you checking if all of the array members are numbers or just filter out the array members that are not number ? — jeremynac, Sep 30 '22 at 09:34
If you had ['John','Olivia','Adam', '1'], should it return ['1']? — jeremynac, Sep 30 '22 at 09:34

score 0 · Answer 1 · answered Sep 30 '22 at 09:37

I hope this snippet does what you want to, or it will lead you towards the solution.

const input = [['2022/10', '2021/05', '2022/01'], ['John','Olivia','Adam'], ['1.23','2.34','101']]

const converted = input.map(array => 
  isNaN(array[0]) ? array : array.map(number => parseFloat(number))
)

console.log(converted)

Alternatively, you can make it more general, so every term will get turned into a number even in array like ['John','2.4','2022/10']:

const input = [['2022/10', '2021/05', '2022/01'], ['John','Olivia','Adam'], ['1.23','2.34','101']]

const converted = input.map(array => 
  array.map(
    numberOrNotNumber => isNaN(numberOrNotNumber) ? numberOrNotNumber : parseFloat(numberOrNotNumber)
  )
)

console.log(converted)

How to check if item of string array can be converted to valid number?

1 Answers1