获取向量元素的输出有问题吗？ [英] Problems with get the output of the elements of a vector?

问题描述

我今天正在使用矢量和课程。我尝试做一些不同的事情，在某种程度上我成功了但是我有这个问题得到最终输出。这就是我所做的 - 我创建了一个类水果然后我创建了一个水果矢量（数据类型）并开始在其中推送不同类型的水果对象。它起作用，完全没有问题。但是，当我想获得向量（水果）中的元素的输出时，我只是无法使用正常方式我得到向量元素输出并且它一直给我错误。这是我的代码 - 请有人建议我在哪里犯了错误 - **我没有在这里包含我的水果类代码

  #include   <   iostream  >  
   #include  < span class =code-preprocessor> <   vector   >  
   #include      fruit.h 
  
 使用 命名空间标准; 
 
  int  main（）
 {
 fruit apple;  //  这是我的水果对象苹果的水果类 
 fruit cherry; 
 vector< fruit>水果; 
 thefruit.push_back（apple）; 
 thefruit.push_back（cherry）; 
 
  for （ int  i =  0 ; i< thefruit.size（）; i ++）
 {
 cout<<  水果向量中的水果是：<< thefruit [i]<< endl;  //  这就是我//得到错误的地方 - 错误是no operator<<匹配这个操作数//  
 
 
} 
 
 system（  pause）; 
 
} 

解决方案

我认为这比我更好地解释和回答你的问题



http://stackoverflow.com/questions/16513046/error- no-operator-matches-these-operands [ ^ ]



'g'

既然你没有编写fruits类的代码，我们就无法100％肯定。但是这个错误很好地解释了这个问题。



如果你不重载<< 班级内的操作员。



与平等，比较和其他操作员相同。



如果您尝试这样做：

  if （thefruit [ 1 ] == thefruit [ 2 ]）
 {
  //  无论 
} 

它将抛出相同的错误，但是没有运算符==而是





查看以下链接：

http：// www .tutorialspoint.com / cplusplus / cpp_overloading.htm [ ^ ]

http://en.cppreference.com/w/ cpp / language / operators [ ^ ]

I was working with vectors and classes today. I tried to do something different and to some extent i was successful but then i have this problem getting the final output. This is what i did- I created a class fruit and then i created a vector of fruit(data-type) and started pushing different types of fruit objects in it. It worked and there was no problem at all. But when i wanted to get the output of the elements in the vector (fruits), i just couldn't use the normal way i get the vector elements output and it kept giving me error. This is my code- Please can someone suggest me where i made the mistake- **I haven't include my fruit class code here

#include <iostream>
#include <vector>
#include "fruit.h"

using namespace std;

int main()
{
  fruit apple; // this is my fruit class with my fruit object apple
fruit cherry;
  vector<fruit> thefruit;
 thefruit.push_back(apple);
thefruit.push_back(cherry);

for(int i=0; i<thefruit.size(); i++)
{
  cout<<"The fruits in the fruit vector are:"<<thefruit[i]<<endl;//this is where i //get the error- The error is" no operator "<<" matches this operands//


}

system("pause");

}

解决方案

I think this explains and answers your question better than I could

http://stackoverflow.com/questions/16513046/error-no-operator-matches-these-operands[^]

'g'

Since you didn't wrote the code of the "fruits" class, we can not be 100% sure. But the error is quite explaining the problem.

You can not print out a class if you don't overload the << operator within the class.

It is the same as with equality, comparison and other operators.

If you try to do:

if (thefruit[1] == thefruit[2])
{
  // whatever
}

It is going to throw the same error but with no operator "==" instead

[edit]
Have a look to following links:
http://www.tutorialspoint.com/cplusplus/cpp_overloading.htm[^]
http://en.cppreference.com/w/cpp/language/operators[^]

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