C ++在方程式中使用变量；错误：表达式必须具有整数或无作用域的枚举类型及其他

Question

srand( 0 );
int points; // number of points
float computerNumber; // number generated by the computer
float guess; // user's guess
char quit; // What the user enters when they want to quit
int totalPoints; //the total score of all of the games played
int avgPoints; // the average score of all games played
int gamesPlayed; // how many games have been played
float rangeLow; // the lower end of the range
float rangeHigh; // the higher end of the range
points = 5;
quit = 'n';
gamesPlayed = 0;
totalPoints = 0;
while ( quit != 'q' )
{

    gamesPlayed++;
    cout << "Welcome to Guessing Game! \n";
    points = 5;
    cout << "What would you like your range to be? \n";
    cout << "Low number: \n";
    cin >> rangeLow;
    cout << "High number: \n";
    cin >> rangeHigh;
    if ( rangeLow > rangeHigh )
    {
        cout << "Please use a high number that is greater than the low number. \n";
        cout << "Low number: \n";
        cin >> rangeLow;
        cout << "High number: \n";
        cin >> rangeHigh;
    }
    else
    {
        ;
    }
    computerNumber = rand( ) % (rangeLow - rangeHigh + 1) + 10;
    cout << "Computer Number: " << computerNumber << endl;
    cout << "Points:" << points << endl;
    cout << "what is your guess? \n" << endl;
    cin >> guess;
    cout << "Your guess is: " << guess << endl;

当我输入此代码（其他不影响这些行的无错误代码行）时，它不会编译并输出两个错误消息-“表达式必须具有整数或无作用域的枚举类型”和“'％ '是非法的，右操作数的类型为'float'“]

我感觉这与在方程式中使用变量有关，但这不应该成为问题吗？所有与该方程式有关的变量类型都是浮点型，我很困惑。

Answer 1

因此，错误是%运算符不能与浮点值一起使用，它只能与integer（int）数据类型一起使用。

您需要将float转换为int，一种方法是使用static_cast<int>(yourFloatNumber)，以便您的计算代码行如下所示：

computerNumber = rand( ) % (static_cast<int>(rangeLow) - static_cast<int>(rangeHigh + 1)) + 10;

模数运算符（％）的要求更为严格，因为操作数必须是整数类型。

Reference