Parse an integer value from the provided 'digits' string.
The string is inspected for a sign and an optional radix
prefix. A radix may be provided as an argument instead,
whereupon it must match the prefix (where present). When
radix is set to zero, conversion will default to decimal.
Parse an integer value from the provided 'digits' string.
The string is inspected for a sign and an optional radix prefix. A radix may be provided as an argument instead, whereupon it must match the prefix (where present). When radix is set to zero, conversion will default to decimal.