c++ 类型转换函数总结

atof()将字符串转换成实数
atoi()将字符串转换成整数
itoa()将整数转换成字符串
ftoa()将实数转换成字符串

布尔值只有1和0，要转换的应该只有和整数一样

 

用string流,直接转换

#include 
#include 
#include 
using namespace std;

void ValToArray()
{
 double x= 43.435;
 int y = 3434;
 bool z = true;
 stringstream ss;
 char str[100];
 ss << x;
 ss >> str;
 cout << str << endl;
 ss.sync();
 ss.clear();
 ss << y;
 ss >> str;
 cout << str << endl;
 ss.sync();
 ss.clear();
 ss << z;
 ss >> str;
 cout << str << endl;
}

void ArrayToVal()
{
 string s;
 bool flag = 0;
 cout << "input a number string: ";
 cin >> s;
 for(string::iterator it = s.begin(); it != s.end(); it++)
 {
  if((*it < '0' || * it > '9') && *it != '.')
  {
   cout << "invalid input !" << endl;
   return;
  }
  if(*it == '.')
   flag = 1;
 }
 stringstream ss;
 if(flag)
 {
  cout << "the val is double: ";
  double x;
  ss.str(s);
  ss >> x;
  cout << x << endl;
 }
 else
 {
  cout << "the val is int: ";
   int y;
  ss.str(s);
  ss >> y;
  cout << y << endl;
 }
}

int main()
{
 ValToArray();  //变量转字符串
 cout << endl;
 ArrayToVal(); //字符串转变量
 return 0;
}