mapintro.cpp

#include<bits/stdc++.h>
using namespace std;


int main()
{
   //Creation
    unordered_map<string,int> m;
  


    //Insertion

    //1
    pair<string,int>p=make_pair("anvi",2);
    m.insert(p);

    //2
    pair<string,int> pair2("haras",2);
    m.insert(pair2);

    //3
    //Creation
    m["love"]=1;

    //What will happen?
    //Upadtion
    m["love"]=3;

    //search
    cout<<m["love"]<<endl;

     //cout<<m.at("UnknownKey")<<endl;
     cout<<m["UnknownKey"]<<endl;

     // and now if we try to print the unknowKey with at
     //Because the key is created
     cout<<m.at("UnknownKey")<<endl;


     //size
    cout<< m.size()<<endl;


    //Chcek presence of Key
    cout<<m.count("love")<<endl;

    //erase
    m.erase("love");
    cout<< m.size()<<endl;

    //Print
    for(auto i:m)
    {
        cout<<i.first<<' '<<i.second<<endl;
    }
    

    //Iterator
unordered_map<string,int> :: iterator it =m.begin();

while(it!=m.end())
{
    cout<<it->first<<" "<<it->second<<endl;
    it++;
}


    return 0;
}