c++ vector容器遍历方式

#include <vector>
 #include <iostream>

class Test
{
public:
    int a;
    int b;
    int c;
    Test()
    {
         a = 0;
         b = 0;
         c = 0; 
     }
}

int main()
{
     vector<Test> vecTest;
    for(int i = 0; i < 5; i++)
    {
         Test temp;
         a=i;
         b=i+1;
         c=i+2;
         vecTest.push_back(temp);
    }  
    std::cout.setf(ios::left);
    std::cout.width(6);

    //一、通过数组下标遍历
    for(int i = 0; i < vecTest.size(); i++)
    {
        std::cout << vecTest[i].a << vecTest[i].b << vecTest[i].c <<std::endl;
     }
  
    //二、通过迭代器遍历
    for(vector<Test>::iterator iter = vecTest.begin();iter != vecTest.end();iter++)
    {
        std::cout << iter->a << iter->b << iter->c <<std::endl;
    }  

    //三、C++11标准，auto关键字遍历
    for(auto iter = vecTest.begin(); iter != vecTest.end(); iter++)
    {
        std::cout << iter->a << iter->b << iter->c <<std::endl;
    }
   
    for(auto i : vecTest)
    {
         std::cout << iter->a << iter->b << iter->c <<std::endl;
    }
}