ParseInt syntax: parseInt (string, radix);
Where string is the string to be converted and radix is binary, octal, hexadecimal or decimal.
When radix is not specified by default, it is hexadecimal when switching with 0x; If it starts with 0 and the second digit is not X, it is considered octal (because octal cannot have 8 or 9, it will return 0 when an error occurs).
I believe you understand this explanation, right?