基於C和C++將int與字符串類型相互轉換

字符串轉int型：

方法1,Use C standard library

#include <iostream>
#include <cstdlib>
#include <string>
    
int main()
{
	std::string text = "123";
	int n = std::atoi(text.c_str());
	std::cout << n << std::endl;
	return 0;
}

方法2,Use C++ standard library std::stringstream

#include <iostream>
#include <string>
#include <sstream>

int main()
 {
	std::string text = "123";
	int n;
	std::istringstream iss (text);
	iss >> n;
	std::cout << n << std::endl;
	return 0;
}

方法3，Use std::stoi() function from C++ standard library since C++11

#include <iostream>
#include <string>

int main ()
{
	std::string str("123");
	int n= std::stoi(str);
	std::cout << n << std::endl;
	return 0;
}

int類型轉字符串：

方法1，Use C standard library

#include <stdio.h>

int main()
{
	const char base_string[] = "base_string";
	char out_string[10];
	int n= 123;
	sprintf(out_string, "%s%d", base_string, n);
	printf("out_string = %s", out_string);
	return 0;
}

方法2，Use C++ standard library std::stringstream

#include <iostream>
#include <sstream>

int main()
{
	int n = 123;
	std::string out_string;
	std::stringstream ss;
	ss << n;
	out_string = ss.str();
	std::cout << "out_string = " << out_string << std::endl;
	return 0;
}

方法3，Use C++ standard library std::to_string() since C++11

#include <iostream>
#include <string>

int main ()
{
	int n = 123;
	std::string out_string = std::to_string(n);
	std::cout << "out_string = " << out_string << std::endl;
	return 0;
}

參考：
https://www.systutorials.com/131/convert-string-to-int-and-reverse/