It is a standardized way to express patterns to be matched against sequences of characters. some of typical regex parameters are as shown below −
Target sequence (subject) − It is used to searched for the sequence pattern.
Regular expression (pattern) − It is used to searched for in the target sequence.
Matches array − Matches information is stored in one of the special match_results array types (such as cmatch or smatch).
Replacement strin − This operation replaces the matches.
Sr.No. | Regex operation & description |
---|---|
1 | regex_match
It is a match sequence. |
2 | regex_search
It is a search sequence. |
3 | regex_replace
It is a replace matched sequence. |
Sr.No. | Iterator type & description |
---|---|
1 | regex_iterator
It is a regex iterator. |
2 | regex_token_iterator
It is a regex token iterator. |
Sr.No. | Instantiation & description |
---|---|
1 | regex
It is a regex class. |
2 | wregex
It is a wregex class. |
Sr.No. | match_results instantiation & description |
---|---|
1 | cmatch
These are match_results for string literals. |
2 | wcmatch
These are match_results for wide string literals. |
3 | smatch
These are match_results for string objects. |
4 | wsmatch
These are match_results for wide string objects. |
Sr.No. | sub_match instantiation & description |
---|---|
1 | csub_match
It is a sub_match for string literals. |
2 | wcsub_match
It is a sub_match for wide string literals. |
3 | ssub_match
It is a sub_match for strings. |
4 | wssub_match
It is a sub_match for wide strings. |
Sr.No. | Namespace & description |
---|---|
1 | regex_constants
It is a regex constants. |