【正则表达式1】C++11正则表达式

头文件

#include <regex>

regex_match：整个字符串是否匹配

regex reg1("\\w+day");
string s1 = "saturday";
string s2 = "saturday and sunday";
smatch r1;
smatch r2;
cout << boolalpha << regex_match(s1, r1, reg1) << endl;　　//true
cout << boolalpha << regex_match(s2, r2, reg1) << endl;　　//false
cout << "s1匹配结果：" << r1.str() << endl;　　　　　　　　　　//saturday
cout << "s2匹配结果：" << r2.str() << endl;　　　　　　　　　　//空
cout << endl;

regex_match：只返回第一个匹配结果

smatch rr1;
smatch rr2;
cout << boolalpha << regex_search(s1, rr1, reg1) << endl;　　//true
cout << "s1匹配结果：" << rr1.str() << endl; 　　　　　　　　　　//saturday
cout << boolalpha << regex_search(s2, rr2, reg1) << endl;　　//true
cout << "s1匹配结果：" << rr2.str() << endl;　　　　　　　　　　 //saturday
cout << endl;

iterator：返回多个匹配结果

类似于指针，调用成员要用"->"

cout << "iterator结果：" << endl;
sregex_iterator it(s2.begin(), s2.end(), reg1);
sregex_iterator end;
for(; it != end; ++it)
{
cout << it->str() << endl;
//cout << *it << endl; 错误
}

cout << "token_iterator结果：" << endl;
sregex_token_iterator tit(s2.begin(), s2.end(), reg1);
sregex_token_iterator tend;
for(; tit != tend; ++tit)
{
cout << tit->str() << endl;
cout << *tit << endl;
}

子表达式匹配

regex reg2("(\\d{1,3}):(\\d{1,3}):(\\d{1,3}):(\\d{1,3})");
string ip = "0:11:222:333";
smatch m;
regex_match(ip, m, reg2);
cout << "输出：str()" << endl;
cout << m.str() << endl;　　 //0:11:222:333
cout << m.str(1) << endl;　　//0
cout << m.str(2) << endl;　　//11
cout << m.str(3) << endl;　　//222
cout << m.str(4) << endl;　　//333

cout << "输出：[i]" << endl; //结果同上
cout << m[0] << endl;
cout << m[1] << endl;
cout << m[2] << endl;
cout << m[3] << endl;
cout << m[4] << endl;

多个匹配结果

string ip2 = "0:11:222:333 4:55:66:7";
sregex_iterator ip_it(ip2.begin(), ip2.end(), reg2);
sregex_iterator ip_end;
for(; ip_it != ip_end; ++ip_it)
{
cout << ip_it->str() << endl;
cout << ip_it->str(1) << endl;
cout << ip_it->str(2) << endl;
cout << ip_it->str(3) << endl;
cout << ip_it->str(4) << endl;
}

总的程序：

#include <iostream>
#include <string>
#include <regex>
using namespace std;

int main()
{
//regex_match匹配整个字符串
regex reg1("\\w+day");
string s1 = "saturday";
string s2 = "saturday and sunday";
smatch r1;
smatch r2;
cout << boolalpha << regex_match(s1, r1, reg1) << endl;
cout << boolalpha << regex_match(s2, r2, reg1) << endl;
cout << "s1匹配结果：" << r1.str() << endl;
cout << "s2匹配结果：" << r2.str() << endl;
cout << endl;

//regex_match只返回第一个匹配结果
smatch rr1;
smatch rr2;
cout << boolalpha << regex_search(s1, rr1, reg1) << endl;
cout << "s1匹配结果：" << rr1.str() << endl;
cout << boolalpha << regex_search(s2, rr2, reg1) << endl;
cout << "s1匹配结果：" << rr2.str() << endl;
cout << endl;

//使用iterator返回多个匹配结果
//结果要用->
cout << "iterator结果：" << endl;
sregex_iterator it(s2.begin(), s2.end(), reg1);
sregex_iterator end;
for(; it != end; ++it)
{
cout << it->str() << endl;
//cout << *it << endl; 错误
}

cout << "token_iterator结果：" << endl;
sregex_token_iterator tit(s2.begin(), s2.end(), reg1);
sregex_token_iterator tend;
for(; tit != tend; ++tit)
{
cout << tit->str() << endl;
cout << *tit << endl;
}

//子表达式匹配
regex reg2("(\\d{1,3}):(\\d{1,3}):(\\d{1,3}):(\\d{1,3})");
string ip = "0:11:222:333";
smatch m;
regex_match(ip, m, reg2);
cout << "输出：str()" << endl;
cout << m.str() << endl;
cout << m.str(1) << endl;
cout << m.str(2) << endl;
cout << m.str(3) << endl;
cout << m.str(4) << endl;

cout << "输出：[i]" << endl;
cout << m[0] << endl;
cout << m[1] << endl;
cout << m[2] << endl;
cout << m[3] << endl;
cout << m[4] << endl;

//输出结果同上
//regex_search(ip, m, str2);
cout << endl;
string ip2 = "0:11:222:333 4:55:66:7";
sregex_iterator ip_it(ip2.begin(), ip2.end(), reg2);
sregex_iterator ip_end;
for(; ip_it != ip_end; ++ip_it)
{
cout << ip_it->str() << endl;
cout << ip_it->str(1) << endl;
cout << ip_it->str(2) << endl;
cout << ip_it->str(3) << endl;
cout << ip_it->str(4) << endl;
}

return 0;

}

View Code

参考：
http://www.cnblogs.com/zhuyp1015/archive/2012/04/08/2438191.html http://www.cnblogs.com/zhuyp1015/archive/2012/04/08/2438215.html