一、int转string
1.c++11标准增加了全局函数std::to_string:
string to_string (int val);
string to_string (long val);
string to_string (long long val);
string to_string (unsigned val);
string to_string (unsigned long val);
string to_string (unsigned long long val);
string to_string (float val);
string to_string (double val);
string to_string (long double val);
Example:
- // to_string example
- #include <iostream> // std::cout
- #include <string> // std::string, std::to_string
- int main ()
- {
- std::string pi = "pi is " + std::to_string(3.1415926);
- std::string perfect = std::to_string(1+2+4+7+14) + " is a perfect number";
- std::cout << pi << '\n';
- std::cout << perfect << '\n';
- return 0;
- }
- pi is 3.141593
- 28 is a perfect number
- ostringstream os; //构造一个输出字符串流,流内容为空
- int i = 12;
- os << i; //向输出字符串流中输出int整数i的内容
- cout << os.str() << endl; //利用字符串流的str函数获取流中的内容
二、string转int
1.可以使用std::stoi/stol/stoll等等函数
Example:
- // stoi example
- #include <iostream> // std::cout
- #include <string> // std::string, std::stoi
- int main ()
- {
- std::string str_dec = "2001, A Space Odyssey";
- std::string str_hex = "40c3";
- std::string str_bin = "-10010110001";
- std::string str_auto = "0x7f";
- std::string::size_type sz; // alias of size_t
- int i_dec = std::stoi (str_dec,&sz);
- int i_hex = std::stoi (str_hex,nullptr,16);
- int i_bin = std::stoi (str_bin,nullptr,2);
- int i_auto = std::stoi (str_auto,nullptr,0);
- std::cout << str_dec << ": " << i_dec << " and [" << str_dec.substr(sz) << "]\n";
- std::cout << str_hex << ": " << i_hex << '\n';
- std::cout << str_bin << ": " << i_bin << '\n';
- std::cout << str_auto << ": " << i_auto << '\n';
- return 0;
- }
- 2001, A Space Odyssey: 2001 and [, A Space Odyssey]
- 40c3: 16579
- -10010110001: -1201
- 0x7f: 127
- string s = "12";
- int a = atoi(s.c_str());
- istringstream is("12"); //构造输入字符串流,流的内容初始化为“12”的字符串
- int i;
- is >> i; //从is流中读入一个int整数存入i中
参考资料:
http://blog.csdn.net/chavo0/article/details/51038397
http://blog.csdn.net/na_beginning/article/details/53576123