ca33a_demo_c++_新旧代码的兼容char数组与vector_string相互转换

/*ca33a_demo_c++33_CppPrimer_新旧代码的兼容_txwtech
旧代码：数组和c风格字符串
新代码：vector和string
相互转换：
c风格字符串<- ->string
数组<- ->vector

C3867错误。
https://docs.microsoft.com/zh-cn/cpp/error-messages/compiler-errors-2/compiler-error-c3867?f1url=https%3A%2F%2Fmsdn.microsoft.com%2Fquery%2Fdev15.query%3FappId%3DDev15IDEF1%26l%3DZH-CN%26k%3Dk(C3867)%26rd%3Dtrue&view=vs-2019
const char *str=st.c_str(); c_str后面的括号不要忘记写上

*/

 /*ca33a_demo_c++33_CppPrimer_新旧代码的兼容_txwtech
 旧代码：数组和c风格字符串
 新代码：vector和string
 相互转换：
 c风格字符串<- ->string
 数组<- ->vector

 C3867错误。
 https://docs.microsoft.com/zh-cn/cpp/error-messages/compiler-errors-2/compiler-error-c3867?f1url=https%3A%2F%2Fmsdn.microsoft.com%2Fquery%2Fdev15.query%3FappId%3DDev15IDEF1%26l%3DZH-CN%26k%3Dk(C3867)%26rd%3Dtrue&view=vs-2019
 const char *str=st.c_str(); c_str后面的括号不要忘记写上

 */

 #include <iostream>
 #include <string>
 #include <vector>
 using namespace std;

 int main()
 {
     string st("Hello World");
     st = st + " bill";
     cout <<"c++:string st: "<< st << endl;

     const char *str=st.c_str();//c++转c风格字符串,必须加上const,常字符指针
     cout << "c风格*str: "<<str << endl;
     //getchar();
     const size_t arr_size = ;
     int int_arr[arr_size] = {,,,,,};
     vector<int> ivec(int_arr, int_arr + arr_size);//数组转vector, int_arr默认指针指向第一个，int_arr + arr_size指向最后一个的后面 [ 开区间，保活。 ）闭区间不包括。前包后不包
     cout << "间隔ivec:" << endl;
     for (vector<int>::iterator itr = ivec.begin(); itr != ivec.end(); ++itr)
     {
         cout << *itr << endl;
     }
     cout << "间隔ivec2:" << endl;
     vector<int> ivec2(int_arr+,int_arr+);//2,3,4的数据赋值到vector
     for (vector<int>::iterator itr = ivec2.begin(); itr != ivec2.end(); ++itr)
     {
         cout << *itr << endl;
     }

     return ;
 }

 /*ca33b_demo_c++_txwtech
 vector数据放入数组
 */
 #include <iostream>
 #include <string>
 #include <vector>

 using namespace std;

 int main()
 {
     vector<int> ivec;
     int ival;

     cout << "Enter number:(Ctrl+Z to end)" << endl;
     while (cin >> ival)
         ivec.push_back(ival);

     int *parr = new int[ivec.size()];//创建动态数组
     size_t ix = ;
     for (vector<int>::iterator iter = ivec.begin(); iter != ivec.end(); ++iter, ++ix)
         parr[ix] = *iter;//vector数据放入数组
     for (ix = ; ix < ivec.size(); ++ix)
     {
         cout <<"vector to 数组" <<*(parr + ix) << endl;
     }
     delete[] parr;
     return ;
 }

/*习题4.34—4.35—c++_txwtech
1.读入一组string数据，放入vector
3.vector字符串->字符指针数组,vector每个字符串--创建新的动态字符数组，
4.vector字符串复制到字符数组
5.字符数组放到动态字符指针数组里面
//cin与getline方法，cin遇到空格就默认一个字符串，getline不识别空格，直到回车，默认一个字符串输入结束
while (getline(cin, str))
svec.push_back(str);
*/

 /*习题4.34—4.35—c++_txwtech
 1.读入一组string数据，放入vector
 3.vector字符串->字符指针数组,vector每个字符串--创建新的动态字符数组，
 4.vector字符串复制到字符数组
 5.字符数组放到动态字符指针数组里面
 //cin与getline方法，cin遇到空格就默认一个字符串，getline不识别空格，直到回车，默认一个字符串输入结束
 */
 #define _CRT_SECURE_NO_WARNINGS
 #include <iostream>
 #include <string>
 #include <vector>

 using namespace std;

 int main()
 {
     vector<string> svec;
     string str;
     cout << "enter strings: (ctrl+Z) to end" << endl;
     //while (cin >> str) //cin与getline方法，cin遇到空格就默认一个字符串，getline不识别空格，直到回车，默认一个字符串输入结束
     while (getline(cin, str))
         svec.push_back(str);//1
     //创建动态字符指针数组
     //数组里面放的指针
     char **parr = new char*[svec.size()];

     size_t ix= ;
     for (vector<string>::iterator iter = svec.begin(); iter != svec.end(); ++iter, ++ix)
     {
         char *p = new char[(*iter).size() + ];//*iter指向的是一个字符串//
         strcpy(p,(*iter).c_str());//vector转c风格//
         parr[ix] = p;//动态字符数组赋值给字符指针//
     }
     cout << "content of vector: " << endl;
     for (vector<string>::iterator iter = svec.begin(); iter != svec.end(); ++iter)
     {
         cout << *iter << endl;
     }
     cout << "Content of charactor arrays: " << endl;
     for (ix = ; ix != svec.size(); ++ix)
     {
         cout << parr[ix] << endl;
     }
     //每个指针delete
     for (ix = ; ix != svec.size(); ++ix)
     {
         delete parr[ix];
     }
     delete[] parr;

         //getchar();
     return ;
 }