如何做这样的事情：“你的号码是“+号码”在 C++ 中？

如何解决如何做这样的事情：“你的号码是“+号码”在 C++ 中？

我最近开始使用 C++，从 JavaScript 开始，所以我有点困惑。

我正在尝试做一个猜数字游戏，而我的实际错误是这样的：

main.cpp:14:67: error: invalid operands of types ‘const char*’ and ‘const char [2]’ to binary ‘operator+’
   cout << "Perfect,Now your playing with numbers up to " + range + "."
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
$ g++ main.cpp
main.cpp: In function ‘int main()’:
main.cpp:14:67: error: invalid operands of types ‘const char*’ and ‘const char [2]’ to binary ‘operator+’
   cout << "Perfect,Now your playing with numbers up to " + range + "."
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~

我不知道它是否有帮助，但我将在下面附上我的代码：

#include <iostream>
using namespace std;

void startGame(int random);
int generateNo(int range);

int main() {
  int range;
  cout << "WELCOME TO  NUMBER GUESSING GAME!" << endl;
  cout << "The calculator is going to generate a random number and you'll have to guess it!" << endl;
  cout << "Please enter the range  of numbers you want to play (ex: 10)" << endl;
  cin >> range;
  int solution = generateNo(range);
  cout << "Perfect,Now your playing with numbers up to " + range + "."
  cout << "GOOD LUCK :)" << endl;

  startGame(solution);

  return 0;
}

int generateNo(int range) {
  return rand() % range + 1;
}

void startGame(int random) {
  int inputNo;

  cin >> inputNo;

  for( int a = 0; ; a++) {
    if(inputNo == random) {
      cout << "Congrats! You've guessed the number!" << endl;
      break;
    } else if(inputNo > random) {
      cout << "Hooolly! WHAT'S with this giant number" << endl;
      startGame(random);
      break;
    } else {
      cout << "Good number,but had your little brain considered to make it bigger!?" << endl;
      startGame(random);
      break;
    }
  }
}

解决方法

您可以将调用链接到 <<：

cout << "Perfect,now your playing with numbers up to " << range << ".";

如果你想先构建一个字符串（这里没有理由这样做），你首先需要构建一个字符串：

std::string text = std::string{"Perfect,now ..."} + std::to_string(range) + ".";
std::cout << text;
    

在您的代码中，您试图添加一个带有整数的字符串文字（类型为 char[N]）。没有 operator+ 将整数连接到字符串文字。

,

C++ 不会在所有任意类型之间重载 + 运算符，并且在您尝试打印时不会将所有内容隐式转换为字符串。幸运的是，对于所有内置类型，您只需使用 << 运算符将它们写入输出流（并为您自己的类型覆盖它）：

cout << "Perfect,now your playing with numbers up to " 
     << range // Note the use of "<<" and not of "+"
     << "."
     << "GOOD LUCK :)"
     << endl;