Regular expressions

Download c++ eBook

Introduction

Regular Expressions (sometimes called regexs or regexps) are a textual syntax which represents the patterns which can be matched in the strings operated upon.

Regular Expressions, introduced in c++11, may optionally support a return array of matched strings or another textual syntax defining how to replace matched patterns in strings operated upon.

Syntax

  • regex_match // Returns whether the entire character sequence was matched by the regex, optionally capturing into a match object
  • regex_search // Returns whether a portion of the character sequence was matched by the regex, optionally capturing into a match object
  • regex_replace // Returns the input character sequence as modified by a regex via a replacement format string
  • regex_token_iterator // Initialized with a character sequence defined by iterators, a list of capture indexes to iterate over, and a regex. Dereferencing returns the currently indexed match of the regex. Incrementing moves to the next capture index or if currently at the last index, resets the index and hinds the next occurrence of a regex match in the character sequence
  • regex_iterator // Initialized with a character sequence defined by iterators and a regex. Dereferencing returns the portion of the character sequence the entire regex currently matches. Incrementing finds the next occurrence of a regex match in the character sequence

Parameters

SignatureDescription
bool regex_match(BidirectionalIterator first, BidirectionalIterator last, smatch& sm, const regex& re, regex_constraints::match_flag_type flags)BidirectionalIterator is any character iterator that provides increment and decrement operators smatch may be cmatch or any other other variant of match_results that accepts the type of BidirectionalIterator the smatch argument may be ommitted if the results of the regex are not needed Returns whether re matches the entire character sequence defined by first and last
bool regex_match(const string& str, smatch& sm, const regex re&, regex_constraints::match_flag_type flags)string may be either a const char* or an L-Value string, the functions accepting an R-Value string are explicitly deleted smatch may be cmatch or any other other variant of match_results that accepts the type of str the smatch argument may be ommitted if the results of the regex are not needed Returns whether re matches the entire character sequence defined by str

Related Examples

Stats

115 Contributors: 4
Friday, June 2, 2017
Licensed under: CC-BY-SA

Not affiliated with Stack Overflow
Rip Tutorial: info@zzzprojects.com

Download eBook