Always pass the radix to parseInt

The `parseInt` method takes two parameters:

parseInt(value, radix);

The second parameter specifies the current numeral system. In the case it's not specified, then it will be set automatically based on the value. If the value starts with `0x` or `0X`, then the radix is 16 (hexadecimal). In other cases, the radix is 10 (decimal).

In the older versions of JavaScript, if the string starts with `0` then the radix is set as 8 (octal).

parseInt('0xF'); // 15
parseInt('0XF'); // 15
parseInt('0xF', 16); // 15

parseInt('0xF', 10); // 0

Since the method could be implemented differently in different versions of JavaScript and browsers, it's recommended to pass the radix number.