Determines whether a character in a string is hexadecimal encoded.
Parameters
pattern
The string to check.
index
The location in pattern to check for hexadecimal encoding.
Returns
bool A bool value that is true if pattern is hexadecimal encoded at the specified location; otherwise, false.
Remarks
The is_hex_encoding method checks for hexadecimal encoding that follows the pattern "%hexhex" in a string, where "hex" is a digit from 0 to 9 or a letter from A-F (case-insensitive).