c++ - read string into array -

i want read string integers , whitespaces array. example have string looks 1 2 3 4 5, , want convert integer array arr[5]={1, 2, 3, 4, 5}. how should that?

i tried delete whitespaces, assign whole 12345 every array element. if don't element assigned 1.

for (int = 0; < str.length(); i++){             if (str[i] == ' ')                 str.erase(i, 1);         }  (int j = 0; j < size; j++){   // size given              arr[j] = atoi(str.c_str());          } 

a couple of notes:

• use std::vector. never know size of input @ compile time. if do, use std::array.
• if have c++11 available you, maybe think stoi or stol, throw upon failed conversion
• you accomplish task std::stringstream allow treat std::string std::istream std::cin. recommend way
• alternatively, go hard route , attempt tokenize std::string based on ' ' delimiter, appears trying do.
• finally, why reinvent wheel if go tokenization route? use boost's split function.

stringstream approach

std::vector<int> readinputfromstream(const std::string& _input, int _num_vals) {     std::vector<int> toreturn;     toreturn.reserve(_num_vals);     std::istringstream fin(_input);     for(int i=0, nextint=0; < _num_vals && fin >> nextint; ++i)     {         toreturn.emplace_back(nextint);     }      // assert (toreturn.size() == _num_vals, "error, stream did not contain enough input")     return toreturn; } 

tokenization approach

std::vector<int> readinputfromtokenizedstring(const std::string& _input, int _num_vals) {     std::vector<int> toreturn;     toreturn.reserve(_num_vals);     char tok = ' '; // whitespace delimiter     size_t beg = 0;     size_t end = 0;     for(beg = _input.find_first_not_of(tok, end); toreturn.size() < static_cast<size_t>(_num_vals) &&     beg != std::string::npos; beg = _input.find_first_not_of(tok, end))     {         end = beg+1;         while(_input[end] == tok && end < _input.size())             ++end;         toreturn.push_back(std::stoi(_input.substr(beg, end-beg)));     }     // assert (toreturn.size() == _num_vals, "error, string did not contain enough input")     return toreturn; } 

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