Java有一个方便的分割方法:
String str = "The quick brown fox";
String[] results = str.split(" ");
在c++中有简单的方法来做到这一点吗?
Java有一个方便的分割方法:
String str = "The quick brown fox";
String[] results = str.split(" ");
在c++中有简单的方法来做到这一点吗?
当前回答
Boost::tokenizer是您的好朋友,但是请考虑使用wstring/wchar_t而不是传统的string/char类型,使您的代码在国际化(i18n)问题上具有可移植性。
#include <iostream>
#include <boost/tokenizer.hpp>
#include <string>
using namespace std;
using namespace boost;
typedef tokenizer<char_separator<wchar_t>,
wstring::const_iterator, wstring> Tok;
int main()
{
wstring s;
while (getline(wcin, s)) {
char_separator<wchar_t> sep(L" "); // list of separator characters
Tok tok(s, sep);
for (Tok::iterator beg = tok.begin(); beg != tok.end(); ++beg) {
wcout << *beg << L"\t"; // output (or store in vector)
}
wcout << L"\n";
}
return 0;
}
其他回答
Boost标记器类可以使这类事情变得非常简单:
#include <iostream>
#include <string>
#include <boost/foreach.hpp>
#include <boost/tokenizer.hpp>
using namespace std;
using namespace boost;
int main(int, char**)
{
string text = "token, test string";
char_separator<char> sep(", ");
tokenizer< char_separator<char> > tokens(text, sep);
BOOST_FOREACH (const string& t, tokens) {
cout << t << "." << endl;
}
}
针对c++ 11更新:
#include <iostream>
#include <string>
#include <boost/tokenizer.hpp>
using namespace std;
using namespace boost;
int main(int, char**)
{
string text = "token, test string";
char_separator<char> sep(", ");
tokenizer<char_separator<char>> tokens(text, sep);
for (const auto& t : tokens) {
cout << t << "." << endl;
}
}
简单的c++代码(标准c++ 98),接受多个分隔符(在std::string中指定),只使用向量、字符串和迭代器。
#include <iostream>
#include <vector>
#include <string>
#include <stdexcept>
std::vector<std::string>
split(const std::string& str, const std::string& delim){
std::vector<std::string> result;
if (str.empty())
throw std::runtime_error("Can not tokenize an empty string!");
std::string::const_iterator begin, str_it;
begin = str_it = str.begin();
do {
while (delim.find(*str_it) == std::string::npos && str_it != str.end())
str_it++; // find the position of the first delimiter in str
std::string token = std::string(begin, str_it); // grab the token
if (!token.empty()) // empty token only when str starts with a delimiter
result.push_back(token); // push the token into a vector<string>
while (delim.find(*str_it) != std::string::npos && str_it != str.end())
str_it++; // ignore the additional consecutive delimiters
begin = str_it; // process the remaining tokens
} while (str_it != str.end());
return result;
}
int main() {
std::string test_string = ".this is.a.../.simple;;test;;;END";
std::string delim = "; ./"; // string containing the delimiters
std::vector<std::string> tokens = split(test_string, delim);
for (std::vector<std::string>::const_iterator it = tokens.begin();
it != tokens.end(); it++)
std::cout << *it << std::endl;
}
这是一个简单的stl解决方案(~5行!)使用std::find和std::find_first_not_of来处理重复的分隔符(例如空格或句号),以及开头和结尾的分隔符:
#include <string>
#include <vector>
void tokenize(std::string str, std::vector<string> &token_v){
size_t start = str.find_first_not_of(DELIMITER), end=start;
while (start != std::string::npos){
// Find next occurence of delimiter
end = str.find(DELIMITER, start);
// Push back the token found into vector
token_v.push_back(str.substr(start, end-start));
// Skip all occurences of the delimiter to find new start
start = str.find_first_not_of(DELIMITER, end);
}
}
现场试试吧!
使用regex_token_iterators的解决方案:
#include <iostream>
#include <regex>
#include <string>
using namespace std;
int main()
{
string str("The quick brown fox");
regex reg("\\s+");
sregex_token_iterator iter(str.begin(), str.end(), reg, -1);
sregex_token_iterator end;
vector<string> vec(iter, end);
for (auto a : vec)
{
cout << a << endl;
}
}
这是一个简单的循环,只对标准库文件进行标记
#include <iostream.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <conio.h>
class word
{
public:
char w[20];
word()
{
for(int j=0;j<=20;j++)
{w[j]='\0';
}
}
};
void main()
{
int i=1,n=0,j=0,k=0,m=1;
char input[100];
word ww[100];
gets(input);
n=strlen(input);
for(i=0;i<=m;i++)
{
if(context[i]!=' ')
{
ww[k].w[j]=context[i];
j++;
}
else
{
k++;
j=0;
m++;
}
}
}