map容器

#include <map>
#include <string>
#include <iostream>
using namespace std;
int main(){
    
    //初始化map
    map<int, string> mapStudent;
    mapStudent.insert(pair<int, string>(1, "student_one"));
    mapStudent.insert(pair<int, string>(2, "student_two"));
    mapStudent.insert(pair<int, string>(3, "student_three"));
    mapStudent.insert(map<int, string>::value_type (4, "student_four"));
    mapStudent.insert(map<int, string>::value_type (5, "student_five"));
    mapStudent.insert(map<int, string>::value_type (6, "student_six"));
    mapStudent[1] = "student_o";
    mapStudent[2] = "student_t";
    mapStudent[3] = "student_t";

    //正序遍历
    map<int, string>::iterator iter;
    for(iter = mapStudent.begin(); iter != mapStudent.end(); iter++)
        cout << iter->first << ' ' << iter->second << endl;

    //逆序遍历
    map<int, string>::reverse_iterator iter2;
    for(iter2 = mapStudent.rbegin(); iter2 != mapStudent.rend(); iter2++)
        cout << iter2->first << " " << iter2->second << endl;

    //数组方式访问
    for(int nindex = 1; nindex <= mapStudent.size(); nindex++)
        cout << mapStudent[nindex] << endl;
    cout << mapStudent.size() << endl << endl;

    //查找key
    iter = mapStudent.find(1);
    if(iter != mapStudent.end())
        cout << "Find, the value is " << iter->second << endl;
    else
        cout << "Do not Find" << endl;

    //删除元素
    iter = mapStudent.find(1);
    mapStudent.erase(iter);
    int n = mapStudent.erase(2);//如果删除了会返回1，否则返回0
    for(iter = mapStudent.begin(); iter != mapStudent.end(); iter++)
        cout << iter->first << ' ' << iter->second << endl;

    //清空
    mapStudent.clear();
    mapStudent.erase( mapStudent.begin(), mapStudent.end() );
    return 0;
}

标签：map,mapStudent,insert,容器,iter2,second,student
来源： https://www.cnblogs.com/ayanyuki/p/15651804.html