在C ++中检索正则表达式搜索 [英] Retrieving a regex search in C++
问题描述
您好我是新的正则表达式,从我从c ++参考网站的理解可以得到匹配的结果。
Hello I am new to regular expressions and from what I understood from the c++ reference website it is possible to get match results.
我的问题是:检索这些结果? smatch
和 cmatch
之间有什么区别?例如,我有一个由日期和时间组成的字符串,这是我写的正则表达式:
My question is: how do I retrieve these results? What is the difference between smatch
and cmatch
? For example, I have a string consisting of date and time and this is the regular expression I wrote:
"(1[0-2]|0?[1-9])([:][0-5][0-9])?(am|pm)"
现在,当我用字符串和上面的表达式做一个 regex_search
时,我可以找到是否有一个时间在字符串或不。但我想把这个时间存储在一个结构中,所以我可以分开的小时和分钟。我使用Visual studio 2010 c ++。
Now when I do a regex_search
with the string and the above expression, I can find whether there is a time in the string or not. But I want to store that time in a structure so I can separate hours and minutes. I am using Visual studio 2010 c++.
推荐答案
std :: regex_search
,然后它填入 std :: match_result
其中可以使用 operator []
以获取匹配的
If you use e.g. std::regex_search
then it fills in a std::match_result
where you can use the operator[]
to get the matched strings.
编辑示例程序:
#include <iostream>
#include <string>
#include <regex>
void test_regex_search(const std::string& input)
{
std::regex rgx("((1[0-2])|(0?[1-9])):([0-5][0-9])((am)|(pm))");
std::smatch match;
if (std::regex_search(input.begin(), input.end(), match, rgx))
{
std::cout << "Match\n";
//for (auto m : match)
// std::cout << " submatch " << m << '\n';
std::cout << "match[1] = " << match[1] << '\n';
std::cout << "match[4] = " << match[4] << '\n';
std::cout << "match[5] = " << match[5] << '\n';
}
else
std::cout << "No match\n";
}
int main()
{
const std::string time1 = "9:45pm";
const std::string time2 = "11:53am";
test_regex_search(time1);
test_regex_search(time2);
}
程序输出:
Match
match[1] = 9
match[4] = 45
match[5] = pm
Match
match[1] = 11
match[4] = 53
match[5] = am
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