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 2.采用sstream中定义的字符串流对象来实现 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; } Output: 2001, A Space Odyssey: 2001 and [, A Space Odyssey] 40c3: 16579 -10010110001: -1201 0x7f: 127 2.采用标准库中atoi函数,对于其他类型也都有相应的标准库函数,比如浮点型atof(),long型atol()等等 string s = "12"; int a = atoi(s.c_str()); 3.采用sstream头文件中定义的字符串流对象来实现转换 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 --------------------- 作者:HarryLi 来源:CSDN 原文:https://blog.csdn.net/u010510020/article/details/73799996 版权声明:本文为博主原创文章,转载请附上博文链接!
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