c/c++各种数据类型转换

1.字符转数字

char a = 'd';
char b = 'm';
int m;
m = a + b - '0';
cout << "m=" << m << endl;

2.数字转字符串

#include<iostream>
#include<cstring>
#include<cstdlib>
#include<sstream>
using namespace std;

int main()
{
  stringstream ss;
  string s;
  int a = 12345;
  ss << a;
  ss >> s;        
}

3.字符串转数字

#include<iostream>
#include<cstring>
#include<cstdlib>
#include<sstream>
using namespace std;

int main()
{
  stringstream ss;
  string s = “12345”;
  int a ;
  ss << s;
  ss >> a;        
}

4.字符转字符串

#include<iostream>
using namespace std;

int main()
{
  char ch = 'a';
  char s[2] = {ch, 0};
  string s1 = s;      
}

重推stringstream类

out_type change(in_type t)
{
  stringstream ss;
  ss << t;  //向流中传值
  out_type result;  //存储转化结果
  ss >> result; //将结果写入result return result; 
  return result;
}