如何在 C++ 中创建类对象的向量？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/21919277/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to create a vector of class objects in C++?
提问by Girardi
I am trying to create a simple stack using vector in C++.
我正在尝试使用 C++ 中的向量创建一个简单的堆栈。
Here is the code:
这是代码：
#include <vector>
class Site
{
public:
int i; // site position i (x-axis)
int s; // site state
vector<Site> neighbors;
Site(void);
Site(int ii, int ss);
void AddNeighbor(Site &site);
};
Site::Site()
{
i = -1;
s = -1;
vector<Site> neighbors;
}
Site::Site(int ii, int ss)
{
i = ii;
s = ss;
}
void Site::AddNeighbor(Site &site)
{
neighbors.push_back(site);
}
void testStack()
{
int tot = 600;
vector<Site> myStack();
int i = 0;
while (i < tot)
{
Site site(i, 1);
myStack.push_back(site);
i++;
}
i = 0;
while (i < tot)
{
Site *site = myStack.back();
myStack.pop_back();
cout << site->i << site->s << endl;
i++;
}
}
Compiler errors:
编译器错误：
ising_wolff.cpp: In function ‘void testStack()': ising_wolff.cpp:373:17: error: request for member ‘push_back' in ‘myStack', which is of non-class type ‘std::vector()' myStack.push_back(site); ^ ising_wolff.cpp:380:30: error: request for member ‘back' in ‘myStack', which is of non-class type ‘std::vector()' Site *site = myStack.back(); ^ ising_wolff.cpp:381:17: error: request for member ‘pop_back' in ‘myStack', which is of non-class type ‘std::vector()' myStack.pop_back();
ising_wolff.cpp：在函数“void testStack()”中：ising_wolff.cpp:373:17：错误：在“myStack”中请求成员“push_back”，它是非类类型“std::vector()”myStack .push_back（网站）；^ ising_wolff.cpp:380:30：错误：在“myStack”中请求成员“back”，它是非类类型“std::vector()” Site *site = myStack.back(); ^ ising_wolff.cpp:381:17: 错误：在“myStack”中请求成员“pop_back”，它是非类类型“std::vector()”myStack.pop_back()；
What do these errors mean?
这些错误是什么意思？
Here are some sites I have looked at:
以下是我看过的一些网站：
1) Creating objects while adding them into vectors
2) push_back causing errors in C
回答by Eric Leschinski
How to create a vector of class objects in C++?
如何在 C++ 中创建类对象的向量？
Start with something simpler so you can get the hang of it.
从更简单的事情开始，这样你就可以掌握它的窍门。
First, create a vector of primitive ints:
首先，创建一个原始整数向量：
#include <vector>
#include <iostream>
using namespace std;
int main(){
vector<int> sites(5);
sites.push_back(5);
for(int x = 0; x < sites.size(); x++){
cout << sites[x];
}
cout << endl;
return 0;
}
Compiling it:
编译它：
g++ -o test test.cpp
Running it:
运行它：
./test
000005
Create a vector of class objects in a similar way as above:
以与上述类似的方式创建类对象的向量：
#include <iostream>
#include <vector>
using namespace std;
class Site {
public:
int i;
};
int main() {
vector<Site> listofsites;
Site *s1 = new Site;
s1->i = 7;
Site *s2 = new Site;
s2->i = 9;
listofsites.push_back(*s1);
listofsites.push_back(*s2);
vector<Site>::iterator it;
for (it = listofsites.begin(); it != listofsites.end(); ++it) {
cout << it->i;
}
return 0;
}
Which should print:
哪个应该打印：
79
回答by Joseph Mansfield
vector<Site> myStack();
This is actually a function declaration. The function is called myStackand it returns a vector<Site>. What you actually want is:
这实际上是一个函数声明。该函数被调用myStack并返回一个vector<Site>. 你真正想要的是：
vector<Site> myStack;
The type of neighboursat the moment will store copies of the objects, not references. If you really want to store references, I recommend using a std::reference_wrapper(rather than using pointers):
目前的类型neighbours将存储对象的副本，而不是引用。如果你真的想存储引用，我建议使用a std::reference_wrapper（而不是使用指针）：
vector<reference_wrapper<Site>> neighbors;
回答by Lightness Races in Orbit
vector<Site> myStack();
This is wrong. Lose the ().
这是错误的。失去().
You're declaring a function, not a vector.
你声明的是一个函数，而不是一个向量。
Just write:
写就好了：
vector<Site> myStack;
回答by Rodrigo Saucedo
You could use:
你可以使用：
vector<Site> myStack;
myStack.resize(100); //will create 100 <Site> objects
