一、数组

#include <iostream>
#include <vector>
using namespace std;
int main()
{int vec[6] = {1,2,3};for (auto num : vec) { /* num 是 int */ cout << "Hello, world!" << num <<endl;}return 0;
}

二、STL容器与迭代器

for 循环

#include <iostream>
#include <vector>
using namespace std;
int main()
{vector<int> vec = {1, 2, 3}; for (auto num : vec) { /* num 是 int */ cout << "Hello, world!" << num <<endl;}return 0;
}

反向迭代器

#include <iostream>
#include <vector>
using namespace std;
int main()
{vector<int> vec = {1, 2, 3}; for (auto rit = vec.rbegin(); rit != vec.rend(); ++rit) {  cout << *rit << " ";  // 逆序输出：3 2 1[6](@ref)  }  return 0;
}