Question

我正在尝试创建一个程序，提示用户输入一个字符串来创建一个非常简单的动画。我的代码工作正常，但是，当我试图显示字符串时，我无法让它工作（第二个功能）请帮助！

 #include <iostream>
 #include <string>
 #include <cmath>

using namespace std;


void getAnimation(string& animation);
void displayAnimation(string& animation);

int main()
{
  string animation;

  getAnimation(animation);

  displayAnimation(animation);

  return 0;
}


//Ask user to enter a single frame 
//returned as string
//Input Parameters: Numeber of Frames, Number of Lines, and Animation 
//Returns: The animation (string)
void getAnimation(string& animation)
{
  int counter, lines, i, numLines, frameNum;

  cout << "How many frames of animation would you like?" << endl;
  cin >> numLines;

  // numbers to help with for - loop
  counter = 0;
  frameNum = 1;

  //for - loop to get information
  for (counter = 0; counter < numLines; counter++)
  {
    cout << "How many lines do you want in this frame?" << endl;
    cin >> lines;

    for (i = 0; i < lines; ++i)
    {
      cout << "Give me line of frame #" << frameNum++ << endl;
      cin >> animation;
      //getline(cin, animation);
      //cin.ignore();
    }
  }
}

//Will gather the string received in main and gather it here to display
//Returned full animation
//Input Parameters: None
//Output Parameters: Animation
void displayAnimation(string& animation)
{
  cout << "Here is your super-sweet animation!\n";

  // to print out entire animation

  //for (auto c : animation)
    //cout << animation << endl;
  //for (int i = 0; i < animation.length(); i++);
}

Answer 1

animation是string不是数组，因此for (auto c : animation)无效。要获得单个字符，只需执行animation.at(i)，其中i是您想要的字符的索引。

您还可以使用stringstream。

char c;
std::istringstream iss(animation)

while (iss.get(c))
{
  // Do animation here
}

不要忘记包含sstream。

您的代码中还有另一个问题。您期望animation能够保留多条输入线，对吧？由于aninamtion是std::string而不是数组或vector，因为我在使用cin >> animation重新计算漏洞时间之前提到过它。您应该使用std::vector<string>进行处理。

所以声明像std::vector<string> animation这样的动画，然后在getAnimation中你需要做类似的事情：

for (i = 0; i < lines; ++i)
{ 
   cout << "Give me line of frame #" << frameNum++ << endl;
   string tmp;
   cin >> tmp;
   animation.push_back(tmp);
}

在displayAnimation中，您应首先遍历vector，然后覆盖它存储的strings以获取单个字符。

for (size_t i = 0; i < animation.size(); ++i)
{
  istringstream iss(animation.at(i));
  char c;
  while (iss.get(c))
  {
    cout << c;
  }
}

您还需要将函数声明更改为void getAnimation(vector<string>& animation)和`void displayAnimation（vector＆amp; animation）

如何在C ++中循环遍历一个字符串并显示一个字符

1 个答案: