C++ unknown error/bug in program flow

I am just reviewing C++ and I don't know why 3 and 5 are the only working option. I already converted it to if-else statement but still the same issue. Below is the code:

#include <iostream>
using namespace std;

int main()
{
    char c, s[50] = {'\0'};
    int num;

    cout << "Select cin method:" << endl;
    cout << "1. cin.get(c);" << endl;
    cout << "2. cin.get(s, 10);" << endl;
    cout << "3. cin.get(s, 10, '*');" << endl;
    cout << "4. cin.getline(s, 10);" << endl;
    cout << "5. cin.read(s, 10);" << endl;
    cout << "Select: " << flush;
    cin >> num;

    switch (num) {
        case 1:
            cin.get(c); //  cin >> c;
            break;
        case 2:
            cin.get(s, 10); //  cin >> s; max length 10, '\n' as string terminator
            break;
        case 3:
            cin.get(s, 10, '*');    //  cin >> s; max length 10, '*' as string terminator
            break;
        case 4:
            cin.getline(s, 10);     //  cin >> s; max length 10, '\n' as string terminator
            break;
        case 5:
            cin.read(s, 10);        //  cin >> s; max length 10, records '\n'
            break;
        default:
            break;
    }

    if (num == 1)
        cout.put(c);                //  cout << s;
    if (num >= 2 && num <= 5)
        cout.write(s, 15);          //  cout << s; max length 15
}