想要更好的学习c++

某商场现有苹果(Apple)、香蕉(Banana)、葡萄(Grape)、橘子(Orange)和梨(Pear)5种水果，从键盘输入某种水果的首字母(大写或小写)，输出相应的英文水果名字(Apple，Banana，Grape，Orange，Pear),若输出的字符不是这几中水果的首字母，则输出Error。
相关知识

#include <iostream>
#include <string>

using namespace std;

int main()
{
    char ch;
  
    cout << "请输入一个水果的首字母：";
    cin >> ch;

    switch (ch)
    {
        case 'A':
        case 'a':
            cout << "Apple" << endl;
            break;
        case 'B':
        case 'b':
            cout << "Banana" << endl;
            break;
        case 'G':
        case 'g':
            cout << "Grape" << endl;
            break;
        case 'O':
        case 'o':
            cout << "Orange" << endl;
            break;
        case 'P':
        case 'p':
            cout << "Pear" << endl;
            break;
        default:
            cout << "Error" << endl;
            break;
    }

    return 0;
}

#include <iostream>
using namespace std;

int main() {
    char ch;
    cout << "请输入某种水果的首字母(大写或小写)：" << endl;
    cin >> ch;

    switch (ch) {
        case 'A':
        case 'a':
            cout << "Apple" << endl;
            break;
        case 'B':
        case 'b':
            cout << "Banana" << endl;
            break;
        case 'G':
        case 'g':
            cout << "Grape" << endl;
            break;
        case 'O':
        case 'o':
            cout << "Orange" << endl;
            break;
        case 'P':
        case 'p':
            cout << "Pear" << endl;
            break;
        default:
            cout << "Error" << endl;
    }

    return 0;
}