C++ Library - <regex>-alljchome-开发者的教程家园

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C++ Library - <regex>

Introduction

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 pterals.
2	wcmatch These are match_results for wide string pterals.
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 pterals.
2	wcsub_match It is a sub_match for wide string pterals.
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.