C++ map的操作

C++中map的常用操作方法，通过代码的方法展现给初学者，希望能帮助到大家

#include <string>#include <map>#include <iostream>using namespace std;int main(){    map<int, string> mapStudent;    //插入方法一    mapStudent.insert(pair<int,string>(1, "student_1"));    mapStudent.insert(pair<int,string>(2, "student_2"));    mapStudent.insert(pair<int,string>(3, "student_3"));    //插入方法二    mapStudent.insert(map<int,string>::value_type(4, "student_4"));    mapStudent.insert(map<int,string>::value_type(5, "student_5"));     mapStudent.insert(map<int,string>::value_type(6, "student_6"));     //插入方法三    mapStudent[7] = "student_7";    mapStudent[8] = "student_8";    mapStudent[9] = "student_9";    //插入方法四,可以判断是否插入成功    pair<map<int, string>::iterator, bool> Insert_Par;    Insert_Par = mapStudent.insert(pair<int, string>(10,"student_10"));    if(Insert_Par.second == true)        cout << "Insert Successfully" <<endl;    else        cout << "Insert failed" <<endl;    //前向迭代器    map<int, string>::iterator iter;    for(iter = mapStudent.begin(); iter != mapStudent.end();iter++)        cout << iter->first << ' '<< iter->second<<endl;    //逆向迭代器    map<int, string>::reverse_iterator iter1;    for(iter1 = mapStudent.rbegin(); iter1 != mapStudent.rend();iter1++)        cout << iter1->first << ' '<< iter1->second<<endl;    //用数组的形式    int nSize = mapStudent.size();    for(int i = 1; i <= nSize; i++)        cout << mapStudent[i]<<endl;    //查找    iter = mapStudent.find(7);    if(iter != mapStudent.end())        cout << "Find, the value is" << iter->second <<endl;    //删除    //通过key删除    int res = mapStudent.erase(1);    // 通过iterator删除    iter = mapStudent.find(2);    mapStudent.erase(iter);    //再次遍历    for(iter = mapStudent.begin(); iter != mapStudent.end();iter++)        cout << iter->first << ' '<< iter->second<<endl;    return 0;}