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;
}
Output:
pi is 3.141593 28 is a perfect number
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;
}
Output:
2001, A Space Odyssey: 2001 and [, A Space Odyssey] 40c3: 16579 -10010110001: -1201 0x7f: 127
原文：https://www.cnblogs.com/kekeoutlook/p/11537715.html