map遍历
测试代码：
1 #include<bits/stdc++.h> 2 using namespace std; 3 void show(map<int,string>& mp) 4 { 5 map<int,string>::iterator iter=mp.begin(); 6 while(iter!=mp.end()) 7 { 8 cout<<iter->first<<" "<<iter->second<<endl; 9 iter++; 10 } 11 cout<<endl; 12 } 13 int main() 14 { 15 //构造 map 16 map<int,string> mp; 17 mp.insert({5,"map 5"});//使用{} 18 mp.insert({6,"map 6"});//使用{} 19 mp.insert({7,"map 7"});//使用{} 20 mp.insert({8,"map 8"});//使用{} 21 mp.insert({0,"map 0"});//使用{} 22 mp.insert({1,"map 1"});//使用{} 23 mp.insert({2,"map 2"});//使用{} 24 mp.insert({3,"map 3"});//使用{} 25 mp.insert({4,"map 4"});//使用{} 26 27 28 //map的遍历 29 for(auto& it:mp) //auto自动识别为迭代器类型 30 { 31 // cout<<it->second<<endl; 32 cout<<it.second<<endl; 33 } 34 cout<<endl; 35 //正向迭代器： 36 map<int,string>::iterator iter=mp.begin(); 37 while(iter != mp.end()) 38 { 39 cout<< " first "<< iter->first << " second "<<iter->second<<std::endl; 40 iter++; 41 } 42 cout<<endl; 43 for(iter=mp.begin();iter!=mp.end();iter++){ 44 cout<< " first "<< iter->first << " second "<<iter->second<<std::endl; 45 } 46 cout<<endl; 47 48 //反向迭代器： 49 map<int,string>::reverse_iterator itera=mp.rbegin(); 50 while(itera != mp.rend()) 51 { 52 cout<< " first "<< itera->first << " second "<<itera->second<<std::endl; 53 itera++; 54 } 55 return 0; 56 }
运行结果：
1 map 0 2 map 1 3 map 2 4 map 3 5 map 4 6 map 5 7 map 6 8 map 7 9 map 8 10 11 first 0 second map 0 12 first 1 second map 1 13 first 2 second map 2 14 first 3 second map 3 15 first 4 second map 4 16 first 5 second map 5 17 first 6 second map 6 18 first 7 second map 7 19 first 8 second map 8 20 21 first 0 second map 0 22 first 1 second map 1 23 first 2 second map 2 24 first 3 second map 3 25 first 4 second map 4 26 first 5 second map 5 27 first 6 second map 6 28 first 7 second map 7 29 first 8 second map 8 30 31 first 8 second map 8 32 first 7 second map 7 33 first 6 second map 6 34 first 5 second map 5 35 first 4 second map 4 36 first 3 second map 3 37 first 2 second map 2 38 first 1 second map 1 39 first 0 second map 0