It always a good practice to pass radix with parseInt –
parseInt(string, radix)
For decimal –
parseInt(id.substring(id.length - 1), 10)
If the radix parameter is omitted, JavaScript assumes the following:
- If the string begins with “0x”, the radix is 16 (hexadecimal)
- If the string begins with “0”, the radix is 8 (octal). This feature is deprecated
- If the string begins with any other value, the radix is 10 (decimal)
(Reference)