A field must contain a complete non-negative decimal integer within the safe range. Which…

A field must contain a complete non-negative decimal integer within the safe range. Which approach matches that contract?

1. Validate String(value) with /^(0|[1-9]\\d*)$/, convert with Number, then call Number.isSafeInteger.
2. Call parseInt(value, 10) and accept any result that is not NaN.
3. Call Number(value) and accept every finite result.
4. Use Boolean(value) before Number(value) to reject empty input.