ignore symbol in regex code example
Example: regex exclude character
[^a] #any character except 'a'
[^aA] #any character except 'a' or 'A'
[^a-z] #any character except a lower case character
[^.] #any character not a period
[^a] #any character except 'a'
[^aA] #any character except 'a' or 'A'
[^a-z] #any character except a lower case character
[^.] #any character not a period