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);
}

当前回答

这类似于堆栈溢出问题:如何在C++中标记字符串?。需要Boost外部库

#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;
    }
}

其他回答

我刚刚写了一个很好的例子,说明如何按符号拆分一个字符,然后将每个字符数组(由符号分隔的单词)放入一个向量中。为了简单起见,我创建了std字符串的向量类型。

我希望这对你有帮助,并且对你可读。

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

void push(std::vector<std::string> &WORDS, std::string &TMP){
    WORDS.push_back(TMP);
    TMP = "";
}
std::vector<std::string> mySplit(char STRING[]){
        std::vector<std::string> words;
        std::string s;
        for(unsigned short i = 0; i < strlen(STRING); i++){
            if(STRING[i] != ' '){
                s += STRING[i];
            }else{
                push(words, s);
            }
        }
        push(words, s);//Used to get last split
        return words;
}

int main(){
    char string[] = "My awesome string.";
    std::cout << mySplit(string)[2];
    std::cin.get();
    return 0;
}

LazyString拆分器:

#include <string>
#include <algorithm>
#include <unordered_set>

using namespace std;

class LazyStringSplitter
{
    string::const_iterator start, finish;
    unordered_set<char> chop;

public:

    // Empty Constructor
    explicit LazyStringSplitter()
    {}

    explicit LazyStringSplitter (const string cstr, const string delims)
        : start(cstr.begin())
        , finish(cstr.end())
        , chop(delims.begin(), delims.end())
    {}

    void operator () (const string cstr, const string delims)
    {
        chop.insert(delims.begin(), delims.end());
        start = cstr.begin();
        finish = cstr.end();
    }

    bool empty() const { return (start >= finish); }

    string next()
    {
        // return empty string
        // if ran out of characters
        if (empty())
            return string("");

        auto runner = find_if(start, finish, [&](char c) {
            return chop.count(c) == 1;
        });

        // construct next string
        string ret(start, runner);
        start = runner + 1;

        // Never return empty string
        // + tail recursion makes this method efficient
        return !ret.empty() ? ret : next();
    }
};

我将此方法称为LazyStringSplitter是因为一个原因——它不会一次性拆分字符串。本质上,它的行为类似于python生成器它公开了一个名为next的方法,该方法返回从原始字符串拆分的下一个字符串我使用了c++11STL中的无序集,因此查找分隔符的速度要快得多下面是它的工作原理

测试程序

#include <iostream>
using namespace std;

int main()
{
    LazyStringSplitter splitter;

    // split at the characters ' ', '!', '.', ','
    splitter("This, is a string. And here is another string! Let's test and see how well this does.", " !.,");

    while (!splitter.empty())
        cout << splitter.next() << endl;
    return 0;
}

输出,输出

This
is
a
string
And
here
is
another
string
Let's
test
and
see
how
well
this
does

改进这一点的下一个计划是实施开始和结束方法,以便可以执行以下操作:

vector<string> split_string(splitter.begin(), splitter.end());

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;
}

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;
}
void splitString(string str, char delim, string array[], const int arraySize)
{
    int delimPosition, subStrSize, subStrStart = 0;

    for (int index = 0; delimPosition != -1; index++)
    {
        delimPosition = str.find(delim, subStrStart);
        subStrSize = delimPosition - subStrStart;
        array[index] = str.substr(subStrStart, subStrSize);
        subStrStart =+ (delimPosition + 1);
    }
}