如何迭代字符串的单词?

[英]How do I iterate over the words of a string?


I'm trying to iterate over the words of a string.

我正在尝试迭代字符串的单词。

The string can be assumed to be composed of words separated by whitespace.

可以假设该字符串由用空格分隔的单词组成。

Note that I'm not interested in C string functions or that kind of character manipulation/access. Also, please give precedence to elegance over efficiency in your answer.

请注意,我对C字符串函数或那种字符操作/访问不感兴趣。另外,请在答案中优先考虑优雅而不是效率。

The best solution I have right now is:

我现在最好的解决方案是:

#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);
}

Is there a more elegant way to do this?

有没有更优雅的方式来做到这一点?

74 个解决方案

#1


1214  

For what it's worth, here's another way to extract tokens from an input string, relying only on standard library facilities. It's an example of the power and elegance behind the design of the STL.

对于它的价值,这是从输入字符串中提取标记的另一种方法,仅依赖于标准库设施。这是STL设计背后的力量和优雅的一个例子。

#include <iostream>
#include <string>
#include <sstream>
#include <algorithm>
#include <iterator>

int main() {
    using namespace std;
    string sentence = "And I feel fine...";
    istringstream iss(sentence);
    copy(istream_iterator<string>(iss),
         istream_iterator<string>(),
         ostream_iterator<string>(cout, "\n"));
}

Instead of copying the extracted tokens to an output stream, one could insert them into a container, using the same generic copy algorithm.

可以使用相同的通用复制算法将提取的令牌复制到容器中,而不是将提取的令牌复制到输出流。

vector<string> tokens;
copy(istream_iterator<string>(iss),
     istream_iterator<string>(),
     back_inserter(tokens));

... or create the vector directly:

...或直接创建矢量:

vector<string> tokens{istream_iterator<string>{iss},
                      istream_iterator<string>{}};

#2


2326  

I use this to split string by a delimiter. The first puts the results in a pre-constructed vector, the second returns a new vector.

我用它来分隔字符串。第一个将结果放在预先构造的向量中,第二个返回一个新向量。

#include <string>
#include <sstream>
#include <vector>
#include <iterator>

template<typename Out>
void split(const std::string &s, char delim, Out result) {
    std::stringstream ss(s);
    std::string item;
    while (std::getline(ss, item, delim)) {
        *(result++) = item;
    }
}

std::vector<std::string> split(const std::string &s, char delim) {
    std::vector<std::string> elems;
    split(s, delim, std::back_inserter(elems));
    return elems;
}

Note that this solution does not skip empty tokens, so the following will find 4 items, one of which is empty:

请注意,此解决方案不会跳过空标记,因此以下内容将找到4个项目,其中一个项目为空:

std::vector<std::string> x = split("one:two::three", ':');

#3


800  

A possible solution using Boost might be:

使用Boost的可能解决方案可能是:

#include <boost/algorithm/string.hpp>
std::vector<std::string> strs;
boost::split(strs, "string to split", boost::is_any_of("\t "));

This approach might be even faster than the stringstream approach. And since this is a generic template function it can be used to split other types of strings (wchar, etc. or UTF-8) using all kinds of delimiters.

这种方法可能比字符串流方法更快。由于这是一个通用模板函数,因此可以使用各种分隔符来分割其他类型的字符串(wchar等或UTF-8)。

See the documentation for details.

有关详细信息,请参阅文档

#4


330  

#include <vector>
#include <string>
#include <sstream>

int main()
{
    std::string str("Split me by whitespaces");
    std::string buf;                 // Have a buffer string
    std::stringstream ss(str);       // Insert the string into a stream

    std::vector<std::string> tokens; // Create vector to hold our words

    while (ss >> buf)
        tokens.push_back(buf);

    return 0;
}

#5


170  

For those with whom it does not sit well to sacrifice all efficiency for code size and see "efficient" as a type of elegance, the following should hit a sweet spot (and I think the template container class is an awesomely elegant addition.):

对于那些不能很好地牺牲代码大小的所有效率并将“高效”视为一种优雅的人来说,下面的内容应该是一个最佳点(我认为模板容器类是一个非常优雅的添加。):

template < class ContainerT >
void tokenize(const std::string& str, ContainerT& tokens,
              const std::string& delimiters = " ", bool trimEmpty = false)
{
   std::string::size_type pos, lastPos = 0, length = str.length();

   using value_type = typename ContainerT::value_type;
   using size_type  = typename ContainerT::size_type;

   while(lastPos < length + 1)
   {
      pos = str.find_first_of(delimiters, lastPos);
      if(pos == std::string::npos)
      {
         pos = length;
      }

      if(pos != lastPos || !trimEmpty)
         tokens.push_back(value_type(str.data()+lastPos,
               (size_type)pos-lastPos ));

      lastPos = pos + 1;
   }
}

I usually choose to use std::vector<std::string> types as my second parameter (ContainerT)... but list<> is way faster than vector<> for when direct access is not needed, and you can even create your own string class and use something like std::list<subString> where subString does not do any copies for incredible speed increases.

我通常选择使用std :: vector 类型作为我的第二个参数(ContainerT)...但是当不需要直接访问时,list <>比vector <>更快,你甚至可以创建你自己的字符串类,并使用像std :: list 之类的东西,其中subString不会做任何副本以获得令人难以置信的速度提升。

It's more than double as fast as the fastest tokenize on this page and almost 5 times faster than some others. Also with the perfect parameter types you can eliminate all string and list copies for additional speed increases.

它比本页面上最快的标记化速度快一倍以上,几乎是其他标记的5倍。此外,使用完美的参数类型,您可以消除所有字符串和列表副本,以提高速度。

Additionally it does not do the (extremely inefficient) return of result, but rather it passes the tokens as a reference, thus also allowing you to build up tokens using multiple calls if you so wished.

此外,它不会(非常低效)返回结果,而是将标记作为参考传递,因此如果您愿意,还可以使用多个调用来构建标记。

Lastly it allows you to specify whether to trim empty tokens from the results via a last optional parameter.

最后,它允许您指定是否通过最后一个可选参数从结果中修剪空标记。

All it needs is std::string... the rest are optional. It does not use streams or the boost library, but is flexible enough to be able to accept some of these foreign types naturally.

它需要的只是std :: string ......其余的都是可选的。它不使用流或boost库,但足够灵活,能够自然地接受这些外来类型中的一些。

#6


153  

Here's another solution. It's compact and reasonably efficient:

这是另一种解决方案。它结构紧凑,效率高:

std::vector<std::string> split(const std::string &text, char sep) {
  std::vector<std::string> tokens;
  std::size_t start = 0, end = 0;
  while ((end = text.find(sep, start)) != std::string::npos) {
    tokens.push_back(text.substr(start, end - start));
    start = end + 1;
  }
  tokens.push_back(text.substr(start));
  return tokens;
}

It can easily be templatised to handle string separators, wide strings, etc.

它可以很容易地进行处理,以处理字符串分隔符,宽字符串等。

Note that splitting "" results in a single empty string and splitting "," (ie. sep) results in two empty strings.

请注意,拆分“”会产生一个空字符串,并且拆分“,”(即sep)会产生两个空字符串。

It can also be easily expanded to skip empty tokens:

它也可以轻松扩展为跳过空标记:

std::vector<std::string> split(const std::string &text, char sep) {
    std::vector<std::string> tokens;
    std::size_t start = 0, end = 0;
    while ((end = text.find(sep, start)) != std::string::npos) {
        if (end != start) {
          tokens.push_back(text.substr(start, end - start));
        }
        start = end + 1;
    }
    if (end != start) {
       tokens.push_back(text.substr(start));
    }
    return tokens;
}

If splitting a string at multiple delimiters while skipping empty tokens is desired, this version may be used:

如果需要在跳过空标记的情况下将字符串拆分为多个分隔符,则可以使用以下版本:

std::vector<std::string> split(const std::string& text, const std::string& delims)
{
    std::vector<std::string> tokens;
    std::size_t start = text.find_first_not_of(delims), end = 0;

    while((end = text.find_first_of(delims, start)) != std::string::npos)
    {
        tokens.push_back(text.substr(start, end - start));
        start = text.find_first_not_of(delims, end);
    }
    if(start != std::string::npos)
        tokens.push_back(text.substr(start));

    return tokens;
}

#7


110  

This is my favorite way to iterate through a string. You can do whatever you want per word.

这是我最喜欢的迭代字符串的方法。你可以随心所欲地做任何事。

string line = "a line of text to iterate through";
string word;

istringstream iss(line, istringstream::in);

while( iss >> word )     
{
    // Do something on `word` here...
}

#8


77  

This is similar to Stack Overflow question How do I tokenize a string in C++?.

这类似于Stack Overflow问题如何在C ++中对字符串进行标记化?

#include <iostream>
#include <string>
#include <boost/tokenizer.hpp>

using namespace std;
using namespace boost;

int main(int argc, char** argv)
{
    string text = "token  test\tstring";

    char_separator<char> sep(" \t");
    tokenizer<char_separator<char>> tokens(text, sep);
    for (const string& t : tokens)
    {
        cout << t << "." << endl;
    }
}

#9


66  

I like the following because it puts the results into a vector, supports a string as a delim and gives control over keeping empty values. But, it doesn't look as good then.

我喜欢以下内容,因为它将结果放入向量中,支持字符串作为delim并控制保持空值。但是,它看起来并不那么好。

#include <ostream>
#include <string>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;

vector<string> split(const string& s, const string& delim, const bool keep_empty = true) {
    vector<string> result;
    if (delim.empty()) {
        result.push_back(s);
        return result;
    }
    string::const_iterator substart = s.begin(), subend;
    while (true) {
        subend = search(substart, s.end(), delim.begin(), delim.end());
        string temp(substart, subend);
        if (keep_empty || !temp.empty()) {
            result.push_back(temp);
        }
        if (subend == s.end()) {
            break;
        }
        substart = subend + delim.size();
    }
    return result;
}

int main() {
    const vector<string> words = split("So close no matter how far", " ");
    copy(words.begin(), words.end(), ostream_iterator<string>(cout, "\n"));
}

Of course, Boost has a split() that works partially like that. And, if by 'white-space', you really do mean any type of white-space, using Boost's split with is_any_of() works great.

当然,Boost有一个split(),其工作方式与此类似。并且,如果通过'white-space',你真的意味着任何类型的空白区域,使用Boost与is_any_of()的分割效果很好。

#10


50  

The STL does not have such a method available already.

STL没有这样的方法。

However, you can either use C's strtok() function by using the std::string::c_str() member, or you can write your own. Here is a code sample I found after a quick Google search ("STL string split"):

但是,您可以通过使用std :: string :: c_str()成员来使用C的strtok()函数,也可以编写自己的函数。以下是我在快速Google搜索后找到的代码示例(“STL字符串拆分”):

void Tokenize(const string& str,
              vector<string>& tokens,
              const string& delimiters = " ")
{
    // Skip delimiters at beginning.
    string::size_type lastPos = str.find_first_not_of(delimiters, 0);
    // Find first "non-delimiter".
    string::size_type pos     = str.find_first_of(delimiters, lastPos);

    while (string::npos != pos || string::npos != lastPos)
    {
        // Found a token, add it to the vector.
        tokens.push_back(str.substr(lastPos, pos - lastPos));
        // Skip delimiters.  Note the "not_of"
        lastPos = str.find_first_not_of(delimiters, pos);
        // Find next "non-delimiter"
        pos = str.find_first_of(delimiters, lastPos);
    }
}

Taken from: http://oopweb.com/CPP/Documents/CPPHOWTO/Volume/C++Programming-HOWTO-7.html

摘自:http://oopweb.com/CPP/Documents/CPPHOWTO/Volume/C++Programming-HOWTO-7.html

If you have questions about the code sample, leave a comment and I will explain.

如果您对代码示例有疑问,请发表评论,我会解释。

And just because it does not implement a typedef called iterator or overload the << operator does not mean it is bad code. I use C functions quite frequently. For example, printf and scanf both are faster than std::cin and std::cout (significantly), the fopen syntax is a lot more friendly for binary types, and they also tend to produce smaller EXEs.

并且因为它没有实现一个名为iterator或者重载的typedef,< <运算符并不意味着它是错误的代码。我经常使用c函数。例如,printf和scanf都比std :: cin和std cout(显着)快,fopen语法对于二进制类型更友好,并且它们也倾向于生成更小的exe。< p>

Don't get sold on this "Elegance over performance" deal.

不要因为这个“优雅而不是表现”的交易而被卖掉。

#11


39  

Here is a split function that:

这是一个拆分函数:

  • is generic
  • uses standard C++ (no boost)
  • 使用标准C ++(没有提升)

  • accepts multiple delimiters
  • 接受多个分隔符

  • ignores empty tokens (can easily be changed)

    忽略空标记(可以很容易地更改)

    template<typename T>
    vector<T> 
    split(const T & str, const T & delimiters) {
        vector<T> v;
        typename T::size_type start = 0;
        auto pos = str.find_first_of(delimiters, start);
        while(pos != T::npos) {
            if(pos != start) // ignore empty tokens
                v.emplace_back(str, start, pos - start);
            start = pos + 1;
            pos = str.find_first_of(delimiters, start);
        }
        if(start < str.length()) // ignore trailing delimiter
            v.emplace_back(str, start, str.length() - start); // add what's left of the string
        return v;
    }
    

Example usage:

    vector<string> v = split<string>("Hello, there; World", ";,");
    vector<wstring> v = split<wstring>(L"Hello, there; World", L";,");

#12


33  

I have a 2 lines solution to this problem:

我有一个解决这个问题的2行解决方案:

char sep = ' ';
std::string s="1 This is an example";

for(size_t p=0, q=0; p!=s.npos; p=q)
  std::cout << s.substr(p+(p!=0), (q=s.find(sep, p+1))-p-(p!=0)) << std::endl;

Then instead of printing you can put it in a vector.

然后,您可以将其放在矢量中,而不是打印。

#13


33  

Yet another flexible and fast way

又一种灵活而快速的方式

template<typename Operator>
void tokenize(Operator& op, const char* input, const char* delimiters) {
  const char* s = input;
  const char* e = s;
  while (*e != 0) {
    e = s;
    while (*e != 0 && strchr(delimiters, *e) == 0) ++e;
    if (e - s > 0) {
      op(s, e - s);
    }
    s = e + 1;
  }
}

To use it with a vector of strings (Edit: Since someone pointed out not to inherit STL classes... hrmf ;) ) :

将它与字符串向量一起使用(编辑:因为某人指出不继承STL类... hrmf;)):

template<class ContainerType>
class Appender {
public:
  Appender(ContainerType& container) : container_(container) {;}
  void operator() (const char* s, unsigned length) { 
    container_.push_back(std::string(s,length));
  }
private:
  ContainerType& container_;
};

std::vector<std::string> strVector;
Appender v(strVector);
tokenize(v, "A number of words to be tokenized", " \t");

That's it! And that's just one way to use the tokenizer, like how to just count words:

而已!这只是使用标记器的一种方法,比如如何计算单词:

class WordCounter {
public:
  WordCounter() : noOfWords(0) {}
  void operator() (const char*, unsigned) {
    ++noOfWords;
  }
  unsigned noOfWords;
};

WordCounter wc;
tokenize(wc, "A number of words to be counted", " \t"); 
ASSERT( wc.noOfWords == 7 );

Limited by imagination ;)

受想象力限制;)

#14


29  

Here's a simple solution that uses only the standard regex library

这是一个只使用标准正则表达式库的简单解决方案

#include <regex>
#include <string>
#include <vector>

std::vector<string> Tokenize( const string str, const std::regex regex )
{
    using namespace std;

    std::vector<string> result;

    sregex_token_iterator it( str.begin(), str.end(), regex, -1 );
    sregex_token_iterator reg_end;

    for ( ; it != reg_end; ++it ) {
        if ( !it->str().empty() ) //token could be empty:check
            result.emplace_back( it->str() );
    }

    return result;
}

The regex argument allows checking for multiple arguments (spaces, commas, etc.)

regex参数允许检查多个参数(空格,逗号等)

I usually only check to split on spaces and commas, so I also have this default function:

我通常只检查分隔空格和逗号,所以我也有这个默认函数:

std::vector<string> TokenizeDefault( const string str )
{
    using namespace std;

    regex re( "[\\s,]+" );

    return Tokenize( str, re );
}

The "[\\s,]+" checks for spaces (\\s) and commas (,).

“[\\ s,] +”检查空格(\\ s)和逗号(,)。

Note, if you want to split wstring instead of string,

注意,如果要拆分wstring而不是string,

  • change all std::regex to std::wregex
  • 将所有std :: regex更改为std :: wregex

  • change all sregex_token_iterator to wsregex_token_iterator
  • 将所有sregex_token_iterator更改为wsregex_token_iterator

Note, you might also want to take the string argument by reference, depending on your compiler.

注意,您可能还希望通过引用获取字符串参数,具体取决于您的编译器。

#15


24  

If you like to use boost, but want to use a whole string as delimiter (instead of single characters as in most of the previously proposed solutions), you can use the boost_split_iterator.

如果您想使用boost,但想要使用整个字符串作为分隔符(而不是像之前提出的大多数解决方案中那样使用单个字符),则可以使用boost_split_iterator。

Example code including convenient template:

示例代码包括方便的模板:

#include <iostream>
#include <vector>
#include <boost/algorithm/string.hpp>

template<typename _OutputIterator>
inline void split(
    const std::string& str, 
    const std::string& delim, 
    _OutputIterator result)
{
    using namespace boost::algorithm;
    typedef split_iterator<std::string::const_iterator> It;

    for(It iter=make_split_iterator(str, first_finder(delim, is_equal()));
            iter!=It();
            ++iter)
    {
        *(result++) = boost::copy_range<std::string>(*iter);
    }
}

int main(int argc, char* argv[])
{
    using namespace std;

    vector<string> splitted;
    split("HelloFOOworldFOO!", "FOO", back_inserter(splitted));

    // or directly to console, for example
    split("HelloFOOworldFOO!", "FOO", ostream_iterator<string>(cout, "\n"));
    return 0;
}

#16


23  

Using std::stringstream as you have works perfectly fine, and do exactly what you wanted. If you're just looking for different way of doing things though, you can use std::find()/std::find_first_of() and std::string::substr().

使用std :: stringstream,你可以完美地工作,并完全按照自己的意愿行事。如果你只是寻找不同的做事方式,你可以使用std :: find()/ std :: find_first_of()和std :: string :: substr()。

Here's an example:

这是一个例子:

#include <iostream>
#include <string>

int main()
{
    std::string s("Somewhere down the road");
    std::string::size_type prev_pos = 0, pos = 0;

    while( (pos = s.find(' ', pos)) != std::string::npos )
    {
        std::string substring( s.substr(prev_pos, pos-prev_pos) );

        std::cout << substring << '\n';

        prev_pos = ++pos;
    }

    std::string substring( s.substr(prev_pos, pos-prev_pos) ); // Last word
    std::cout << substring << '\n';

    return 0;
}

#17


18  

There is a function named strtok.

有一个名为strtok的函数。

#include<string>
using namespace std;

vector<string> split(char* str,const char* delim)
{
    char* saveptr;
    char* token = strtok_r(str,delim,&saveptr);

    vector<string> result;

    while(token != NULL)
    {
        result.push_back(token);
        token = strtok_r(NULL,delim,&saveptr);
    }
    return result;
}

#18


17  

Heres a regex solution that only uses the standard regex library. (I'm a little rusty, so there may be a few syntax errors, but this is at least the general idea)

这是一个仅使用标准正则表达式库的正则表达式解决方案。 (我有点生疏,所以可能会有一些语法错误,但这至少是一般的想法)

#include <regex.h>
#include <string.h>
#include <vector.h>

using namespace std;

vector<string> split(string s){
    regex r ("\\w+"); //regex matches whole words, (greedy, so no fragment words)
    regex_iterator<string::iterator> rit ( s.begin(), s.end(), r );
    regex_iterator<string::iterator> rend; //iterators to iterate thru words
    vector<string> result<regex_iterator>(rit, rend);
    return result;  //iterates through the matches to fill the vector
}

#19


15  

The stringstream can be convenient if you need to parse the string by non-space symbols:

如果需要使用非空格符号解析字符串,则stringstream可以很方便:

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, ';')

#20


14  

So far I used the one in Boost, but I needed something that doesn't depends on it, so I came to this:

到目前为止,我使用了Boost中的那个,但是我需要一些不依赖它的东西,所以我来到这里:

static void Split(std::vector<std::string>& lst, const std::string& input, const std::string& separators, bool remove_empty = true)
{
    std::ostringstream word;
    for (size_t n = 0; n < input.size(); ++n)
    {
        if (std::string::npos == separators.find(input[n]))
            word << input[n];
        else
        {
            if (!word.str().empty() || !remove_empty)
                lst.push_back(word.str());
            word.str("");
        }
    }
    if (!word.str().empty() || !remove_empty)
        lst.push_back(word.str());
}

A good point is that in separators you can pass more than one character.

一个好处是,在分隔符中,您可以传递多个字符。

#21


13  

I've rolled my own using strtok and used boost to split a string. The best method I have found is the C++ String Toolkit Library. It is incredibly flexible and fast.

我使用strtok自己滚动并使用boost来分割字符串。我找到的最好的方法是C ++ String Toolkit Library。它非常灵活和快速。

#include <iostream>
#include <vector>
#include <string>
#include <strtk.hpp>

const char *whitespace  = " \t\r\n\f";
const char *whitespace_and_punctuation  = " \t\r\n\f;,=";

int main()
{
    {   // normal parsing of a string into a vector of strings
        std::string s("Somewhere down the road");
        std::vector<std::string> result;
        if( strtk::parse( s, whitespace, result ) )
        {
            for(size_t i = 0; i < result.size(); ++i )
                std::cout << result[i] << std::endl;
        }
    }

    {  // parsing a string into a vector of floats with other separators
        // besides spaces

        std::string s("3.0, 3.14; 4.0");
        std::vector<float> values;
        if( strtk::parse( s, whitespace_and_punctuation, values ) )
        {
            for(size_t i = 0; i < values.size(); ++i )
                std::cout << values[i] << std::endl;
        }
    }

    {  // parsing a string into specific variables

        std::string s("angle = 45; radius = 9.9");
        std::string w1, w2;
        float v1, v2;
        if( strtk::parse( s, whitespace_and_punctuation, w1, v1, w2, v2) )
        {
            std::cout << "word " << w1 << ", value " << v1 << std::endl;
            std::cout << "word " << w2 << ", value " << v2 << std::endl;
        }
    }

    return 0;
}

The toolkit has much more flexibility than this simple example shows but its utility in parsing a string into useful elements is incredible.

该工具包比这个简单的示例具有更大的灵活性,但它在将字符串解析为有用元素方面的实用性令人难以置信。

#22


13  

Short and elegant

短而优雅

#include <vector>
#include <string>
using namespace std;

vector<string> split(string data, string token)
{
    vector<string> output;
    size_t pos = string::npos; // size_t to avoid improbable overflow
    do
    {
        pos = data.find(token);
        output.push_back(data.substr(0, pos));
        if (string::npos != pos)
            data = data.substr(pos + token.size());
    } while (string::npos != pos);
    return output;
}

can use any string as delimiter, also can be used with binary data (std::string supports binary data, including nulls)

可以使用任何字符串作为分隔符,也可以与二进制数据一起使用(std :: string支持二进制数据,包括空值)

using:

auto a = split("this!!is!!!example!string", "!!");

output:

this
is
!example!string

#23


11  

I made this because I needed an easy way to split strings and c-based strings... Hopefully someone else can find it useful as well. Also it doesn't rely on tokens and you can use fields as delimiters, which is another key I needed.

我这样做是因为我需要一种简单的方法来分割字符串和基于c的字符串......希望其他人也能发现它很有用。它也不依赖于令牌,你可以使用字段作为分隔符,这是我需要的另一个键。

I'm sure there's improvements that can be made to even further improve its elegance and please do by all means

我相信可以进一步改善其优雅的改进,请务必做

StringSplitter.hpp:

#include <vector>
#include <iostream>
#include <string.h>

using namespace std;

class StringSplit
{
private:
    void copy_fragment(char*, char*, char*);
    void copy_fragment(char*, char*, char);
    bool match_fragment(char*, char*, int);
    int untilnextdelim(char*, char);
    int untilnextdelim(char*, char*);
    void assimilate(char*, char);
    void assimilate(char*, char*);
    bool string_contains(char*, char*);
    long calc_string_size(char*);
    void copy_string(char*, char*);

public:
    vector<char*> split_cstr(char);
    vector<char*> split_cstr(char*);
    vector<string> split_string(char);
    vector<string> split_string(char*);
    char* String;
    bool do_string;
    bool keep_empty;
    vector<char*> Container;
    vector<string> ContainerS;

    StringSplit(char * in)
    {
        String = in;
    }

    StringSplit(string in)
    {
        size_t len = calc_string_size((char*)in.c_str());
        String = new char[len + 1];
        memset(String, 0, len + 1);
        copy_string(String, (char*)in.c_str());
        do_string = true;
    }

    ~StringSplit()
    {
        for (int i = 0; i < Container.size(); i++)
        {
            if (Container[i] != NULL)
            {
                delete[] Container[i];
            }
        }
        if (do_string)
        {
            delete[] String;
        }
    }
};

StringSplitter.cpp:

#include <string.h>
#include <iostream>
#include <vector>
#include "StringSplit.hpp"

using namespace std;

void StringSplit::assimilate(char*src, char delim)
{
    int until = untilnextdelim(src, delim);
    if (until > 0)
    {
        char * temp = new char[until + 1];
        memset(temp, 0, until + 1);
        copy_fragment(temp, src, delim);
        if (keep_empty || *temp != 0)
        {
            if (!do_string)
            {
                Container.push_back(temp);
            }
            else
            {
                string x = temp;
                ContainerS.push_back(x);
            }

        }
        else
        {
            delete[] temp;
        }
    }
}

void StringSplit::assimilate(char*src, char* delim)
{
    int until = untilnextdelim(src, delim);
    if (until > 0)
    {
        char * temp = new char[until + 1];
        memset(temp, 0, until + 1);
        copy_fragment(temp, src, delim);
        if (keep_empty || *temp != 0)
        {
            if (!do_string)
            {
                Container.push_back(temp);
            }
            else
            {
                string x = temp;
                ContainerS.push_back(x);
            }
        }
        else
        {
            delete[] temp;
        }
    }
}

long StringSplit::calc_string_size(char* _in)
{
    long i = 0;
    while (*_in++)
    {
        i++;
    }
    return i;
}

bool StringSplit::string_contains(char* haystack, char* needle)
{
    size_t len = calc_string_size(needle);
    size_t lenh = calc_string_size(haystack);
    while (lenh--)
    {
        if (match_fragment(haystack + lenh, needle, len))
        {
            return true;
        }
    }
    return false;
}

bool StringSplit::match_fragment(char* _src, char* cmp, int len)
{
    while (len--)
    {
        if (*(_src + len) != *(cmp + len))
        {
            return false;
        }
    }
    return true;
}

int StringSplit::untilnextdelim(char* _in, char delim)
{
    size_t len = calc_string_size(_in);
    if (*_in == delim)
    {
        _in += 1;
        return len - 1;
    }

    int c = 0;
    while (*(_in + c) != delim && c < len)
    {
        c++;
    }

    return c;
}

int StringSplit::untilnextdelim(char* _in, char* delim)
{
    int s = calc_string_size(delim);
    int c = 1 + s;

    if (!string_contains(_in, delim))
    {
        return calc_string_size(_in);
    }
    else if (match_fragment(_in, delim, s))
    {
        _in += s;
        return calc_string_size(_in);
    }

    while (!match_fragment(_in + c, delim, s))
    {
        c++;
    }

    return c;
}

void StringSplit::copy_fragment(char* dest, char* src, char delim)
{
    if (*src == delim)
    {
        src++;
    }

    int c = 0;
    while (*(src + c) != delim && *(src + c))
    {
        *(dest + c) = *(src + c);
        c++;
    }
    *(dest + c) = 0;
}

void StringSplit::copy_string(char* dest, char* src)
{
    int i = 0;
    while (*(src + i))
    {
        *(dest + i) = *(src + i);
        i++;
    }
}

void StringSplit::copy_fragment(char* dest, char* src, char* delim)
{
    size_t len = calc_string_size(delim);
    size_t lens = calc_string_size(src);

    if (match_fragment(src, delim, len))
    {
        src += len;
        lens -= len;
    }

    int c = 0;
    while (!match_fragment(src + c, delim, len) && (c < lens))
    {
        *(dest + c) = *(src + c);
        c++;
    }
    *(dest + c) = 0;
}

vector<char*> StringSplit::split_cstr(char Delimiter)
{
    int i = 0;
    while (*String)
    {
        if (*String != Delimiter && i == 0)
        {
            assimilate(String, Delimiter);
        }
        if (*String == Delimiter)
        {
            assimilate(String, Delimiter);
        }
        i++;
        String++;
    }

    String -= i;
    delete[] String;

    return Container;
}

vector<string> StringSplit::split_string(char Delimiter)
{
    do_string = true;

    int i = 0;
    while (*String)
    {
        if (*String != Delimiter && i == 0)
        {
            assimilate(String, Delimiter);
        }
        if (*String == Delimiter)
        {
            assimilate(String, Delimiter);
        }
        i++;
        String++;
    }

    String -= i;
    delete[] String;

    return ContainerS;
}

vector<char*> StringSplit::split_cstr(char* Delimiter)
{
    int i = 0;
    size_t LenDelim = calc_string_size(Delimiter);

    while(*String)
    {
        if (!match_fragment(String, Delimiter, LenDelim) && i == 0)
        {
            assimilate(String, Delimiter);
        }
        if (match_fragment(String, Delimiter, LenDelim))
        {
            assimilate(String,Delimiter);
        }
        i++;
        String++;
    }

    String -= i;
    delete[] String;

    return Container;
}

vector<string> StringSplit::split_string(char* Delimiter)
{
    do_string = true;
    int i = 0;
    size_t LenDelim = calc_string_size(Delimiter);

    while (*String)
    {
        if (!match_fragment(String, Delimiter, LenDelim) && i == 0)
        {
            assimilate(String, Delimiter);
        }
        if (match_fragment(String, Delimiter, LenDelim))
        {
            assimilate(String, Delimiter);
        }
        i++;
        String++;
    }

    String -= i;
    delete[] String;

    return ContainerS;
}

Examples:

int main(int argc, char*argv[])
{
    StringSplit ss = "This:CUT:is:CUT:an:CUT:example:CUT:cstring";
    vector<char*> Split = ss.split_cstr(":CUT:");

    for (int i = 0; i < Split.size(); i++)
    {
        cout << Split[i] << endl;
    }

    return 0;
}

Will output:

This
is
an
example
cstring

这是一个cstring示例

int main(int argc, char*argv[])
{
    StringSplit ss = "This:is:an:example:cstring";
    vector<char*> Split = ss.split_cstr(':');

    for (int i = 0; i < Split.size(); i++)
    {
        cout << Split[i] << endl;
    }

    return 0;
}

int main(int argc, char*argv[])
{
    string mystring = "This[SPLIT]is[SPLIT]an[SPLIT]example[SPLIT]string";
    StringSplit ss = mystring;
    vector<string> Split = ss.split_string("[SPLIT]");

    for (int i = 0; i < Split.size(); i++)
    {
        cout << Split[i] << endl;
    }

    return 0;
}

int main(int argc, char*argv[])
{
    string mystring = "This|is|an|example|string";
    StringSplit ss = mystring;
    vector<string> Split = ss.split_string('|');

    for (int i = 0; i < Split.size(); i++)
    {
        cout << Split[i] << endl;
    }

    return 0;
}

To keep empty entries (by default empties will be excluded):

保留空条目(默认情况下将排除空白):

StringSplit ss = mystring;
ss.keep_empty = true;
vector<string> Split = ss.split_string(":DELIM:");

The goal was to make it similar to C#'s Split() method where splitting a string is as easy as:

目标是使其类似于C#的Split()方法,其中拆分字符串就像:

String[] Split = 
    "Hey:cut:what's:cut:your:cut:name?".Split(new[]{":cut:"}, StringSplitOptions.None);

foreach(String X in Split)
{
    Console.Write(X);
}

I hope someone else can find this as useful as I do.

我希望其他人能像我一样认为这很有用。

#24


10  

What about this:

那这个呢:

#include <string>
#include <vector>

using namespace std;

vector<string> split(string str, const char delim) {
    vector<string> v;
    string tmp;

    for(string::const_iterator i; i = str.begin(); i <= str.end(); ++i) {
        if(*i != delim && i != str.end()) {
            tmp += *i; 
        } else {
            v.push_back(tmp);
            tmp = ""; 
        }   
    }   

    return v;
}

#25


9  

Here's another way of doing it..

这是另一种做法..

void split_string(string text,vector<string>& words)
{
  int i=0;
  char ch;
  string word;

  while(ch=text[i++])
  {
    if (isspace(ch))
    {
      if (!word.empty())
      {
        words.push_back(word);
      }
      word = "";
    }
    else
    {
      word += ch;
    }
  }
  if (!word.empty())
  {
    words.push_back(word);
  }
}

#26


9  

I like to use the boost/regex methods for this task since they provide maximum flexibility for specifying the splitting criteria.

我喜欢使用boost / regex方法执行此任务,因为它们为指定拆分条件提供了最大的灵活性。

#include <iostream>
#include <string>
#include <boost/regex.hpp>

int main() {
    std::string line("A:::line::to:split");
    const boost::regex re(":+"); // one or more colons

    // -1 means find inverse matches aka split
    boost::sregex_token_iterator tokens(line.begin(),line.end(),re,-1);
    boost::sregex_token_iterator end;

    for (; tokens != end; ++tokens)
        std::cout << *tokens << std::endl;
}

#27


9  

Recently I had to split a camel-cased word into subwords. There are no delimiters, just upper characters.

最近我不得不将一个带有骆驼字的单词分成子字。没有分隔符,只有上面的字符。

#include <string>
#include <list>
#include <locale> // std::isupper

template<class String>
const std::list<String> split_camel_case_string(const String &s)
{
    std::list<String> R;
    String w;

    for (String::const_iterator i = s.begin(); i < s.end(); ++i) {  {
        if (std::isupper(*i)) {
            if (w.length()) {
                R.push_back(w);
                w.clear();
            }
        }
        w += *i;
    }

    if (w.length())
        R.push_back(w);
    return R;
}

For example, this splits "AQueryTrades" into "A", "Query" and "Trades". The function works with narrow and wide strings. Because it respects the current locale it splits "RaumfahrtÜberwachungsVerordnung" into "Raumfahrt", "Überwachungs" and "Verordnung".

例如,这将“AQueryTrades”拆分为“A”,“查询”和“交易”。该函数适用于窄字符串和宽字符串。因为它尊重当前的地点,所以它将“RaumfahrtÜberwachungsVerordnung”分为“Raumfahrt”,“Überwachungs”和“Verordnung”。

Note std::upper should be really passed as function template argument. Then the more generalized from of this function can split at delimiters like ",", ";" or " " too.

注意std :: upper应该真的作为函数模板参数传递。然后,这个函数的更一般化可以分裂为“,”,“;”等分隔符。或者“”。

#28


9  

This answer takes the string and puts it into a vector of strings. It uses the boost library.

这个答案接受字符串并将其放入字符串向量中。它使用boost库。

#include <boost/algorithm/string.hpp>
std::vector<std::string> strs;
boost::split(strs, "string to split", boost::is_any_of("\t "));

#29


8  

Get Boost ! : -)

得到提升! : - )

#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string.hpp>
#include <iostream>
#include <vector>

using namespace std;
using namespace boost;

int main(int argc, char**argv) {
    typedef vector < string > list_type;

    list_type list;
    string line;

    line = "Somewhere down the road";
    split(list, line, is_any_of(" "));

    for(int i = 0; i < list.size(); i++)
    {
        cout << list[i] << endl;
    }

    return 0;
}

This example gives the output -

这个例子给出了输出 -

Somewhere
down
the
road

#30


8  

The code below uses strtok() to split a string into tokens and stores the tokens in a vector.

下面的代码使用strtok()将字符串拆分为标记并将标记存储在向量中。

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;


char one_line_string[] = "hello hi how are you nice weather we are having ok then bye";
char seps[]   = " ,\t\n";
char *token;



int main()
{
   vector<string> vec_String_Lines;
   token = strtok( one_line_string, seps );

   cout << "Extracting and storing data in a vector..\n\n\n";

   while( token != NULL )
   {
      vec_String_Lines.push_back(token);
      token = strtok( NULL, seps );
   }
     cout << "Displaying end result in vector line storage..\n\n";

    for ( int i = 0; i < vec_String_Lines.size(); ++i)
    cout << vec_String_Lines[i] << "\n";
    cout << "\n\n\n";


return 0;
}
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