C++吧的第一帖，不要从入门到放弃

从c++primer plus第5章课后习题开始吧，前面的都学过很多，而且自己刚重新又看到这里，开始学习

5.9中的第7题，2个问题，交替读取字符串和数字有问题，中间的换行符虽然不需要但是还是起作用，怎么解决。还有结构数组不能定义动态的吗，智能定义固定的。

终于弄明白了，原来是输入数字后再输入字符串的话会有回车符起作用。会产生问题。

#include "pch.h"
#include <iostream>
#include <string>
using namespace std;
struct CAR
{
string name;
int per_year;
};
int main()
{
int num;
cout << "How many cars do you wish to catalog? ";
cin >> num;
cin.get();
//CAR *ps = new CAR[num];A
CAR car[10];
//cin >> (s_car[0]).name;
//delete[] s_car;
for (int i = 0; i < num; i++)
{
cout << "Car #" << i+1<<endl;
cout << "Please enter the make:";
getline(cin,car[1].name);
cout << "Please enter the year made: ";
cin >> car[i].per_year;
cin.get();
};
cout << "Here is your collection: " << endl;
for (int i = 0;i<num;i++)
{
cout << car[i].per_year << " " << car[i].name << endl;
}
cout << "Done. " << endl;
return 0;
}
结果：
问题：为什么第一个里面没有输入的q，解决不了这个bug

第8题
#include "pch.h"
#include <iostream>
#include <cstring>
using namespace std;
int main()
{
cout << "Enter words (to stop, type the word done): " << endl;
char *cword = new char[128];
int i = 0;
do
{
cin >> cword;
++i;
} while (strcmp(cword,"done"));
cout << i-1 << endl;
return 0;
}

5.9 exercise10
#include "pch.h"
#include <iostream>
using namespace std;
int main()
{
cout << "Enter number of rows :";
int n_row;
cin >> n_row;
int i = 0;
for (;i<=n_row;i++)
{
for (int ii= n_row-i;ii>0;ii--)
{
cout << ".";
}
for (int iii = 0;iii<=i; iii++)
{
cout << "*";
}
cout << endl;
}
return 0;
}

#include "pch.h"
#include <iostream>
using namespace std;
int main()
{
double d1[10] = {};
for (int i = 0;i<10;i++)
{
cin >> d1[i];
if (isdigit(d1[i]))
{
cout << 1 << endl;
}
else
cout << 2 << endl;
}
return 0;
}

怎么判断不了，就是输入1会变成2，只能输入-1到255之间的数，isdigit这个函数的范围的确是有限的，但是怎么识别不了我的1呢，1会变false