Last Example about switch&do while

#include<iostream>
using namespace std;
void op_fun(int c)
{
    int x,y;
    switch(c)
    {
        //if the user choose 1
        case 1:
            cout<<"\n-----------------------------------------------\n";
            cout<<"Addition";
            cout<<"\n-----------------------------------------------\n";
            cout<<"Enter First Number : "; cin>>x;
            cout<<"Enter Second Number : "; cin>>y;
            cout<<"The Resualt is : "<<x+y<<endl;
            cout<<"\n-----------------------------------------------\n";
        break;
        //if the user choose 2
        case 2:
            cout<<"\n-----------------------------------------------\n";
            cout<<"Subtraction";
            cout<<"\n-----------------------------------------------\n";
            cout<<"Enter First Number : "; cin>>x;
            cout<<"Enter Second Number : "; cin>>y;
            cout<<"The Resualt is : "<<x-y<<endl;
            cout<<"\n-----------------------------------------------\n";
        break;
        //if the user choose 3
        case 3:
            cout<<"\n-----------------------------------------------\n";
            cout<<"Multiple";
            cout<<"\n-----------------------------------------------\n";
            cout<<"Enter First Number : "; cin>>x;
            cout<<"Enter Second Number : "; cin>>y;
            cout<<"The Resualt is : "<<x*y<<endl;
            cout<<"\n-----------------------------------------------\n";
        break;

        default:
            cout<<"End of programm ";

    }
}
int main()
{
    int c;
    //we uses do while for looping this
    do
    {
        cout<<"1 :Addition \t 2 :Subtraction \t 3 :Multiple \t 4 :Exit \n";
        cout<<"Choose : ";
        cin>>c;
        op_fun(c);
    }while(c!=4);
}