- Metacharacters - SubExpression Grouping
- (...) ?+* Extend Quantifiers
/^(anti)?social$/ antisocial social /^([0-9]{3}[-. ]?){1,2}[0-9]{4}$/ 248-555-1212 313.555.1212 5865551212 734 2997650
/^(anti)?social$/ antisocial social /^([0-9]{3}[-. ]?){1,2}[0-9]{4}$/ 248-555-1212 313.555.1212 5865551212 734 2997650