转自:http://blog.csdn.net/sunshinewave/article/details/8067862
#include<iostream>
#include<map>
#include<algorithm>
using namespace std;
int main()
{
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"));
map<int,string>::iterator iter;
for(iter=mapstudent.begin();iter!=mapstudent.end();iter++)
{
cout<<iter->first<<" "<<iter->second<<endl;
}
cout<<endl;
mapstudent[1]="student_one";
mapstudent[2]="student_two";
mapstudent[3]="student_three";
for(iter=mapstudent.begin();iter!=mapstudent.end();iter++)
{
cout<<iter->first<<" "<<iter->second<<endl;
}
int map_size=mapstudent.size();
cout<<map_size<<endl;
mapstudent.clear();
if(mapstudent.empty())
cout<<"lalalala"<<endl;
}