C++ 将 std::string 拆分为 vector<string> 的正确方法

Right way to split an std::string into a vector<string>

提问by devnull

Possible Duplicate:
How to split a string?

可能的重复：
如何拆分字符串？

What is the right way to split a string into a vector of strings. Delimiter is space or comma.

将字符串拆分为字符串向量的正确方法是什么。分隔符是空格或逗号。

回答by UncleBens

A convenient way would be boost's string algorithms library.

一种方便的方法是boost 的字符串算法库。

#include <boost/algorithm/string/classification.hpp> // Include boost::for is_any_of
#include <boost/algorithm/string/split.hpp> // Include for boost::split
// ...

std::vector<std::string> words;
std::string s;
boost::split(words, s, boost::is_any_of(", "), boost::token_compress_on);

回答by Nawaz

For space separated strings, then you can do this:

对于空格分隔的字符串，您可以这样做：

std::string s = "What is the right way to split a string into a vector of strings";
std::stringstream ss(s);
std::istream_iterator<std::string> begin(ss);
std::istream_iterator<std::string> end;
std::vector<std::string> vstrings(begin, end);
std::copy(vstrings.begin(), vstrings.end(), std::ostream_iterator<std::string>(std::cout, "\n"));

Output:

输出：

What
is
the
right
way
to
split
a
string
into
a
vector
of
strings

---

---

string that have both comma and space

包含逗号和空格的字符串

struct tokens: std::ctype<char> 
{
    tokens(): std::ctype<char>(get_table()) {}

    static std::ctype_base::mask const* get_table()
    {
        typedef std::ctype<char> cctype;
        static const cctype::mask *const_rc= cctype::classic_table();

        static cctype::mask rc[cctype::table_size];
        std::memcpy(rc, const_rc, cctype::table_size * sizeof(cctype::mask));

        rc[','] = std::ctype_base::space; 
        rc[' '] = std::ctype_base::space; 
        return &rc[0];
    }
};

std::string s = "right way, wrong way, correct way";
std::stringstream ss(s);
ss.imbue(std::locale(std::locale(), new tokens()));
std::istream_iterator<std::string> begin(ss);
std::istream_iterator<std::string> end;
std::vector<std::string> vstrings(begin, end);
std::copy(vstrings.begin(), vstrings.end(), std::ostream_iterator<std::string>(std::cout, "\n"));

Output:

输出：

right
way
wrong
way
correct
way

回答by Tod

If the string has both spaces and commas you can use the string class function

如果字符串同时包含空格和逗号，则可以使用字符串类函数

found_index = myString.find_first_of(delims_str, begin_index) 

in a loop. Checking for != npos and inserting into a vector. If you prefer old school you can also use C's

在一个循环中。检查 != npos 并插入向量。如果你更喜欢老派，你也可以使用 C

strtok() 

method.

方法。

回答by Shiqi Ai

vector<string> split(string str, string token){
    vector<string>result;
    while(str.size()){
        int index = str.find(token);
        if(index!=string::npos){
            result.push_back(str.substr(0,index));
            str = str.substr(index+token.size());
            if(str.size()==0)result.push_back(str);
        }else{
            result.push_back(str);
            str = "";
        }
    }
    return result;
}

split("1,2,3",",") ==> ["1","2","3"]

split("1,2,",",") ==> ["1","2",""]

split("1token2token3","token") ==> ["1","2","3"]

split("1,2,3",",") ==> ["1","2","3"]

split("1,2,",",") ==> ["1","2",""]

split("1token2token3","token") ==> ["1","2","3"]

回答by James LT

You can use getline with delimiter:

您可以使用带有分隔符的 getline：

string s, tmp; 
stringstream ss(s);
vector<string> words;

while(getline(ss, tmp, ',')){
    words.push_back(tmp);
    .....
}

回答by wcochran

Tweaked version from Techie Delight:

来自Techie Delight 的调整版本：

#include <string>
#include <vector>

std::vector<std::string> split(const std::string& str, char delim) {
    std::vector<std::string> strings;
    size_t start;
    size_t end = 0;
    while ((start = str.find_first_not_of(delim, end)) != std::string::npos) {
        end = str.find(delim, start);
        strings.push_back(str.substr(start, end - start));
    }
    return strings;
}

回答by Ankit Baid

i made this custom function that will convert the line to vector

我制作了这个自定义函数，它将线转换为向量

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

using namespace std;

int main(){

    string line;
    getline(cin, line);
    int len = line.length();
    vector<string> subArray;

    for (int j = 0, k = 0; j < len; j++) {
        if (line[j] == ' ') {
            string ch = line.substr(k, j - k);
            k = j+1;
            subArray.push_back(ch);
        }
        if (j == len - 1) {
            string ch = line.substr(k, j - k+1);
            subArray.push_back(ch);
        }
    }

    return 0;
}