Regex.cpp

#include <iostream>
#include <string>
#include <regex>

int main()
{
	//string that we want to find matches in
	std::string string =	"The dog went to the dog park. "
				"There were numerous other doggies";
	
	//the object we want to hold matches in
	//called smatch because it holds matches that were found in a string
	//hence the 's' followed by match
	std::smatch match;

	//the pattern we want to find within the string
	//the question mark means that (gies) is optional
	//so this means we want to "match dog" or "doggies"
	std::regex pattern("dog(gies)?");

	//sregex iterator ( 's' is for string )
	//sregex iterator returns a bool that indicated if it found a match
	//the iterator has a member function called str() that returns the most recent match
	//the iterator itself is a pointer so we have to access using iterator->str() or (*iterator).str()
	//the "end" variable defaults to a end of string iterator
	//notice that we create 2 sregex_iterators within the for loop's initialization portion
	//repeat until no more matches are found
	for (std::sregex_iterator iterator(string.cbegin(), string.cend(), pattern), end;
	     iterator != end; ++iterator)
	{
		//print the match we just found
		std::cout << iterator->str() << std::endl;
	}

	std::cin.get();	//wait until user presses any key so that the program ends
}