C++ if 语句中的多个条件

我对 C++ 编程的概念非常陌生。我想要使​​用多条件 if 语句||（或）和&&（和）在一份声明中。当我向我的大学教授询问此事时。她告诉我这是可能的，然后侮辱了我在这个问题上有限的知识。我有权访问的所有示例都显示了多个 && 语句，并且只有一个显示了||。它没有显示它们被一起使用。我想了解如何让生产线正常工作。我将附上我的代码。问题区域是编码的最后一位。

# include <iostream>
# include <cstring>

using namespace std;

main()
{
    
    const int maximumHours = 774;
    char customerPackage;
    double hoursUsed = 0,
           packageA = 9.95,
           packageB = 14.95,
           packageC = 19.95,
           overPackageA = 2.00,
           overPackageB = 1.00,
           overTime = 0,
           amountDue = 0,
           excessCharged = 0;
    
    cout << "Please enter the customer's package: ";
    cin >> customerPackage;
    
    switch (customerPackage)
    {
        case 'a' :
            cout << "Please enter the number of hours used: ";
                cin >> hoursUsed;
            break;
        
        case 'A' :
            cout << "Please enter the number of hours used: ";
                cin >> hoursUsed;
            break;
        
        case 'b' :
            cout << "Please enter the number of hours used: ";
                cin >> hoursUsed;
            break;
        
        case 'B' :
            cout << "Please enter the number of hours used: ";
                cin >> hoursUsed;
            break;
          
        case 'c' :
            cout << "Please enter the number of hours used: ";
                cin >> hoursUsed;
            break;
        
        case 'C' :
            cout << "Please enter the number of hours used: ";
            cin >> hoursUsed;
            break;        
        default: cout << "Error." 
            << " Please enter the customer's purchased package: ";
        cin >> customerPackage;
    }    
            
    if ( customerPackage ='a' || customerPackage ='A' && hoursUsed >= 10)           
        amountDue = packageA;
        else
            overTime = packageA - hoursUsed;
            excessCharged = overTime * overPackageA;
            amountDue = packageA + excessCharged;
}

你的问题是&&优先级高于||所以你需要括号。正如评论中所述，您还需要使用==而不是赋值（=):

if ( (customerPackage =='a' || customerPackage =='A') && hoursUsed >= 10)