# Removes all non-alphanumeric characters from a string, returning a new string
# containing only letters and numbers.
#
# @param input_string [String] The source string containing punctuation, symbols, and spaces.
# @return [String] A new string containing only alphanumeric characters.
# @raise [TypeError] If the input is not a String.
def remove_non_alphanumeric(input_string)
# Guard clause: validate input type
unless input_string.is_a?(String)
raise TypeError, "Input must be a valid String."
end
# Use gsub with the [:alnum:] POSIX character class negated ([^...])
# to replace all non-alphanumeric characters with an empty string.
input_string.gsub(/[^[:alnum:]]/, '')
end
# --- Example Usage ---
if __FILE__ == $PROGRAM_NAME
begin
text = "Hello, World! 123_#$ Ruby-Programming."
# Process the string
cleaned_text = remove_non_alphanumeric(text)
# Output results
puts "Original: #{text}"
puts "Cleaned: #{cleaned_text}"
rescue StandardError => e
warn "Error: #{e.message}"
exit(1)
end
end
# run:
#
# Original: Hello, World! 123_#$ Ruby-Programming.
# Cleaned: HelloWorld123RubyProgramming
#
