c++ - 你如何修复 C++ 预期的主表达式错误？

Question

所以，我是 C++ 编程的新手，作为一项作业，我的老师让我们创建一个应用程序。我开始编码，这就是我想出的。我尝试在 CodeBlocks 中编译代码，但它给了我很多错误:

错误:'petProfile' 之前需要主表达式在 int main() 中，在 switch 语句的情况 1 到情况 3 中。

错误:“(*(petProfile + ((sizetype) ((unsigned int)petIndex) * 4u))))->Pet::vaccNames = nextVaccN”中的“operator=”不匹配 它来自这行代码:petProfile[petIndex]->vaccNames = nextVaccN;

相同类型的错误:petProfile[petIndex]->vaccDates = nextVaccD;

并且，petProfile[petIndex]->timeBetween = nextTimeDiff;

如果我能得到任何帮助，我将不胜感激，谢谢。

//Constant

const int maxNumOfPet = 8;

//Functions

void newProfile(Pet petProfile);

void updateExist(Pet petProfile);

void viewPetFile(Pet petProfile);

void howToUse();

int main()
{
    int usersOption;
    int* optionPointer = &usersOption;
    Pet petProfile[maxNumOfPet];

    //the do while loop will start here, it will display the start menu, and  direct to the different functions
    //until the user selects to exit.
    do
    {
        //Displays the different options to the user.
        cout << "\n1) Create New Pet Profile" << endl;
        cout << "2) Update A Existing Profile" << endl;
        cout << "3) View A Pet Profile" << endl;
        cout << "4) How To Use" << endl;
        cout << "5) Quit" << endl;

        cout << "Please pick the option you wish to do." << endl;
        cin >> *optionPointer;

        switch (usersOption)
        {
        case 1:
            newProfile(Pet petProfile);
            break;
        case 2:
            updateExist(Pet petProfile);
            break;
        case 3:
            viewPetFile(Pet petProfile);
            break;
        case 4:
            howToUse();
            break;
        case 5:
            cout << "Bye, Bye!";
            return 0;
        }   //End of Switch Statement
    } while (usersOption >= 1 || usersOption < 5);

    return 0;
}

void newProfile(Pet *petProfile[], const int maxNumOfPet)
{
    int changeOp;
    int nextVaccD;
    char correct;
    double nextTimeDiff;
    string nextVaccN;
    int petIndex = 0;

    while (petIndex <= maxNumOfPet)
    {
        //check if Pet is empty
        while (petProfile[petIndex]->petNames.empty())
        {
            //Will receive the users input for the following topics, and add it   to their vectors.

            cout << "Please enter your pet's name, Or enter 0 to quit. " <<   endl;
            if ( cin.peek() == '\n' )
                cin.ignore();

            string nextPetN;
            getline(cin, nextPetN);

            if (nextPetN == "0")
                return;

            //Will add an element to the vector petNames and save the users input to it.
            petProfile[petIndex]->petNames = nextPetN;

            cout << "Please enter the type of animal you have:" << endl;
            if ( cin.peek() == '\n' )
                cin.ignore();

            string nextAnimalT;
            getline(cin, nextAnimalT);

            //Will add an element to the vector animalType and save the users input to it.
            petProfile[petIndex]->animalType = nextAnimalT;

            cout << "Please enter the name of a vaccine the pet has got: " << endl;
            cin >> nextVaccN;

            //Will add an element to the vector vaccNames and save the users input to it.
            petProfile[petIndex]->vaccNames = nextVaccN;

            cout << "Please enter the date " << nextVaccN << " was given, in this format MMDDYYYY." << endl;
            cin >> nextVaccD;

            //Will add an element to the vector vaccDates and save the users input to it.
            petProfile[petIndex]->vaccDates = nextVaccD;

            cout << "Please enter the time difference between each administration of this vaccine: " << endl;
            cin >> nextTimeDiff;

            //Will add an element to the vector timeBetween and save the users input to it.
            petProfile[petIndex]->timeBetween = nextTimeDiff;

            //Recap the information entered, and change if it is necessary.
            cout << "\nSo far you entered: " << endl;
            cout << nextPetN << endl;
            cout << nextAnimalT << endl;
            cout << nextVaccN << endl;
            cout << nextVaccD << endl;
            cout << nextTimeDiff << endl;

            cout << "Is this information correct?" << endl;
            cout << "Answer T if this is true or F if this is false" << endl;
            cin >> correct;

            if (correct == 'F' || correct == 'f')
            {
                cout << "What do you wish to change: " << endl;
                cout << "1) " << nextPetN << endl;
                cout << "2) " << nextAnimalT << endl;
                cout << "3) " << nextVaccN << endl;
                cout << "4) " << nextVaccD << endl;
                cout << "5) " << nextTimeDiff << endl;
                cin >> changeOp;

                switch (changeOp)
                {
                case 1:
                    cout << "Please enter your pets' name: " << endl;
                    getline(cin, nextPetN);
                    break;

                case 2:
                    cout << "Please enter the type of animal you have:" << endl;
                    getline(cin, nextAnimalT);
                    break;

                case 3:
                    cout << "Please enter the name of the vaccines the pet has got: " << endl;
                    getline(cin, nextVaccN);
                    break;

                case 4:
                    cout << "Please enter the date " << nextVaccN << " was given, in this format MMDDYYYY." << endl;
                    cin >> nextVaccD;
                    break;

                case 5:
                    cout << "Please enter the time difference between each administration of this vaccine: " << endl;
                    cin >> nextTimeDiff;
                    break;
                } //end switch
            } //end if statement
        }//end second while loop
    } //end first while loop

    petIndex++;
} //end newProfile function

Answer 1

你的函数声明

void newProfile(Pet petProfile);

不符合定义

void newProfile(Pet *petProfile[], const int maxNumOfPet)

另外，行

case 1:
        newProfile(Pet petProfile);

应该是

case 1:
        newProfile(petProfile); // no Pet here, same for the other case-s

检查您的其他函数声明是否与其定义匹配。