c++正则表达式
#include <regex> using namespace std; void out(bool b) { cout << (b ? "found" : "not found") << endl; } int _tmain(int argc, _TCHAR* argv[]) { regex reg1("<.*>.*</.*>"); // 常规匹配 bool found = regex_match("<tag>test c++ regexp</tag1>",reg1); out(found); regex reg2("<(.*)>.*</\\1>"); // 就配对解析而言, 一定得失前向引用 found = regex_match("<tag>test c++ regexp</tag1>",reg2); out(found); }
输出:
out found
found
第二种比较常见的用法是找出所有匹配的串,如下:
string data="<person>\n" "<first>张</first>" "<last>三</last>" "</person>"; regex reg3("<(.*)>(.*)</\\1>"); sregex_iterator pos(data.cbegin(),data.cend(),reg3); sregex_iterator end2; for(;pos!=end2;++pos) { cout << "match:" << pos->str() << endl; cout << " tag:" << pos->str(1) << endl; cout << "value:" << pos->str(2) << endl; }
输出:
match:<first>张</first> tag:first value:张 match:<last>三</last> tag:last value:三