用stringstream类，口诀：过滤一下就转化

头文件#include<sstream>

例子：将整数12和浮点数12.34转化为字符串

int main()
{
	int x = 12;
	double d = 12.34;
	string s;
	//创建一下对象str
	stringstream str;
	//过滤一下就转化
	str << x;
	str >> s;
	for (int i = 0; i < s.size(); i++)
	{
		cout << s[i] << " ";
	}
	cout << endl;
	//清空一下str
	str.clear();
	//过滤一下就转化
	str << d;
	str >> s;
	for (int i = 0; i < s.size(); i++)
	{
		cout << s[i] << " ";
	}
	cout << endl;

	return 0;
}

结果

 将字符串转换为整数（浮点数）

例子：将字符串“12”和“12.34”转换为整型和浮点型

int main()
{
	int x = 0;
	double d = 0;
	string s1 = "12";
	string s2 = "12.34";
	//创建一下对象str
	stringstream str;
	//过滤一下就转化
	str << s1;
	str >> x;
	cout << x << endl;
	//清空一下str
	str.clear();
	//过滤一下就转化
	str << s2;
	str >> d;
	cout << d << endl;

	return 0;
}

结果