如何迭代由空格分隔的单词组成的字符串中的单词?
注意,我对C字符串函数或那种字符操作/访问不感兴趣。比起效率,我更喜欢优雅。我当前的解决方案:
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
int main() {
string s = "Somewhere down the road";
istringstream iss(s);
do {
string subs;
iss >> subs;
cout << "Substring: " << subs << endl;
} while (iss);
}
#include <iostream>
#include <regex>
using namespace std;
int main() {
string s = "foo bar baz";
regex e("\\s+");
regex_token_iterator<string::iterator> i(s.begin(), s.end(), e, -1);
regex_token_iterator<string::iterator> end;
while (i != end)
cout << " [" << *i++ << "]";
}
IMO,这是最接近python的re.split()。有关regex_token_iterator的更多信息,请参阅cplusplus.com。-1(regex_token_iterator tor中的第四个参数)是序列中不匹配的部分,使用匹配作为分隔符。
如果您需要通过非空格符号解析字符串,则字符串流可能很方便:
string s = "Name:JAck; Spouse:Susan; ...";
string dummy, name, spouse;
istringstream iss(s);
getline(iss, dummy, ':');
getline(iss, name, ';');
getline(iss, dummy, ':');
getline(iss, spouse, ';')
我的代码是:
#include <list>
#include <string>
template<class StringType = std::string, class ContainerType = std::list<StringType> >
class DSplitString:public ContainerType
{
public:
explicit DSplitString(const StringType& strString, char cChar, bool bSkipEmptyParts = true)
{
size_t iPos = 0;
size_t iPos_char = 0;
while(StringType::npos != (iPos_char = strString.find(cChar, iPos)))
{
StringType strTemp = strString.substr(iPos, iPos_char - iPos);
if((bSkipEmptyParts && !strTemp.empty()) || (!bSkipEmptyParts))
push_back(strTemp);
iPos = iPos_char + 1;
}
}
explicit DSplitString(const StringType& strString, const StringType& strSub, bool bSkipEmptyParts = true)
{
size_t iPos = 0;
size_t iPos_char = 0;
while(StringType::npos != (iPos_char = strString.find(strSub, iPos)))
{
StringType strTemp = strString.substr(iPos, iPos_char - iPos);
if((bSkipEmptyParts && !strTemp.empty()) || (!bSkipEmptyParts))
push_back(strTemp);
iPos = iPos_char + strSub.length();
}
}
};
例子:
#include <iostream>
#include <string>
int _tmain(int argc, _TCHAR* argv[])
{
DSplitString<> aa("doicanhden1;doicanhden2;doicanhden3;", ';');
for each (std::string var in aa)
{
std::cout << var << std::endl;
}
std::cin.get();
return 0;
}
这里有一个拆分函数:
是通用的使用标准C++(无增强)接受多个分隔符忽略空标记(可以轻松更改)模板<typename T>矢量<T>拆分(常量T&str,常量T&分隔符){向量<T>v;typename T::size_type start=0;自动位置=str.find_first_of(分隔符,开始);而(pos!=T::npos){if(pos!=开始)//忽略空标记v.template_back(str,start,pos-start);开始=位置+1;pos=str.find_first_of(分隔符,开始);}if(start<str.length())//忽略尾随分隔符v.template_back(str,start,str.length()-start);//添加字符串的剩余部分返回v;}
示例用法:
vector<string> v = split<string>("Hello, there; World", ";,");
vector<wstring> v = split<wstring>(L"Hello, there; World", L";,");
我使用这个simpleton是因为我们得到了字符串类“特殊”(即非标准):
void splitString(const String &s, const String &delim, std::vector<String> &result) {
const int l = delim.length();
int f = 0;
int i = s.indexOf(delim,f);
while (i>=0) {
String token( i-f > 0 ? s.substring(f,i-f) : "");
result.push_back(token);
f=i+l;
i = s.indexOf(delim,f);
}
String token = s.substring(f);
result.push_back(token);
}