用isalnum拆分字符串并存储到字符串向量中

Question

我正在处理一个字符串，并尝试在它不是字母数字（不是 a-z、A-Z 和 0-9）时将其分解。我发现 isalnum 是一个有用的函数。

例如，如果我有字符串 "bob-michael !#mi%@pa hi3llary-tru1mp"

矢量应包含：bob、michael、mi、pa、hi3llary 和 tru1mp。

我当前的代码是：

  vector<string> result;
  string something = "bob-michael !#mi%@pa hi3llary-tru1mp";
  stringstream pie(something);
  //not sure what to do after this point(I know, not a lot. See below for my current thinking)

我的想法是使用一个循环，当 isalnum 结果为 1 时继续向前，如果 isalnum 结果为 0，则将我到目前为止的任何内容推入字符串向量。也许我可以使用 isalnum 作为 delim？我很难接受我的想法并写下这篇文章。谁能指出我正确的方向？谢谢！

编辑：感谢大家的帮助。

Answer 1

大概是这样的：

std::vector<std::string> result;
std::string something = "bob-michael !#mi%@pa hi3llary-tru1mp";
std::regex token("[A-Za-z0-9]+");

std::copy(
    std::sregex_token_iterator(something.begin(), something.end(), token),
    std::sregex_token_iterator(),
    std::back_inserter(result));

Demo

Answer 2

你也可以遍历字符串，然后检查当前索引是否为字母，如果不是则将其分解然后存储到向量

std::string something = "bob-michael !#mi%@pa hi3llary-tru1mp";

std::vector<std::string> result;

std::string newResult = "";

for ( int a = 0; a < something.size(); a++ )
{
      if((something[a] >= 'a' && something[a] <= 'z')||(something[a] >= 'A' && something[a] <= 'Z')
          || (something[a] >= '0' && something[a] <= '9'))
      {
          newResult += something[a];
      }
      else
      {
         if(newResult.size() > 0)
         {
            result.push_back(newResult);
            newResult = "";
         }
      }
}
result.push_back(newResult);

Answer 3

std::replace_if trick I commented on turned out to not be quite as trivial as I thought it was because std::isalnum 没有 return bool。

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

int main()
{
    std::vector<std::string> result;
    std::string something = "bob-michael !#mi%@pa hi3llary-tru1mp";
    // I expected replace_if(something.begin(), something.end(), &isalnum, " ");
    // would work, but then I did a bit of reading and found is alnum returned int,
    // not bool. resolving this by wrapping isalnum in a lambda
    std::replace_if(something.begin(),
                    something.end(),
                    [](char val)->bool {
                          return std::isalnum(val) == 0;
                     },
                     ' ');
    std::stringstream pie(something);

    // read stream into vector
    std::copy(std::istream_iterator<std::string>(pie),
              std::istream_iterator<std::string>(),
              std::back_inserter<std::vector<std::string>>(result));

    // prove it works
    for(const std::string & str: result)
    {
        std::cout << str << std::endl;
    }
}

用isalnum拆分字符串并存储到字符串向量中

Splitting a string withisalnum and store into a vector of strings

c++

string

parsing

stringstream