c++11 auto 遍历map，vector

#include <iostream>#include <map>#include <queue>using namespace std;int main(){    map<int,string> student;    student.insert(pair<int,string>(2,"li"));    student.insert(pair<int,string>(1,"wang"));    student.insert(pair<int,string>(3,"sun"));    for(auto &v : student)    cout<<v.first<<endl;    return 0;}

输出：

由此可见，遍历的时候是按key值进行遍历。

#include <iostream>#include <map>#include <queue>#include <vector>using namespace std;int main(){   vector<int> q;   q.push_back(3);   q.push_back(1);   q.push_back(2);   for(auto &v : q)    cout<<v<<endl;   vector<int>w[3];   w[0].push_back(3);   w[0].push_back(1);   w[0].push_back(2);   for(auto &v : w[0])    cout<<v<<endl;    return 0;}