C++ - Program to Make Simple calculator in C++

Write a program and call it calc.cpp which is the basic calculator and receives three values from input via keyboard.

The first value as an operator (Op1) should be a char type and one of (+, -, *, /, s) characters with the following meanings:
- ‘+’ for addition (num1 + num2)
- ‘-’ for subtraction (num1 – num2)
- ‘*’ for multiplication (num1 * num2)
- ‘/’ for division (num1 / num2)
- ‘s’ for swap
Program should receive another two operands (Num1, Num2) which could be float or integer.
The program should apply the first given operator (Op1) into the operands (Num1, Num2) and prints the relevant results with related messages in the screen.
Swap operator exchanges the content (swap) of two variables, for this task you are not allowed to use any further variables (You should use just two variables to swap).

#include<iostream>
#include<cmath>

using namespace std;

int main()
{
    //-------defining variables and initializing them-------------
    double num1,num2;
    char operation,redo;
    //--------Printing my name on screen----------------
    cout<<"Welcome to the calculater program v.1.0 written by Your Name"<<endl;
    cout<<"***************************************************************"<<endl;
    cout<<endl<<endl<<endl;
    //--here do loop is used so that the program can be used more then one time
    //without exiting the run screen---------------------------
    do
    {
        //----receiving the variables from input--------------
        cout<<" Please enter an operation which you like to calculate (+,-,*,/,s)";
        cout<<"[s stands for swap]:";
        cin>>operation ;
        cout<<endl<<endl;
        cout<<" Please enter two numbers to apply your requested operation(";
        cout<<operation<<"):"<<endl<<"1st num:";
        cin>>num1;
        cout<<"2nd num:" ;
        cin>>num2;
        cout<<endl;
        //---used switch function so thet the operater can be decided------------
        switch (operation)
        {
        //------calculating the requested equation for inputs-------------
        //-------at the same time printing the results on screen-----------
        case'+':
            cout<<"The addition of two numbers ("<<num1<<","<<num2<<"):";
            cout<<num1+num2<<endl;
            break;
        case'-':
            cout<<"The substraction of two numbers ("<<num1<<","<<num2<<"):";
            cout<<num1-num2<<endl;
            break;
        case'*':
            cout<<"The multiplication of two numbers ("<<num1<<","<<num2<<"):";
            cout<<num1*num2<<endl;
            break;
        case'/':
            cout<<"The division of two numbers ("<<num1<<","<<num2<<"):";
            if(num2==0)
            {
                cout<<"not valid"<<endl;
            }
            cout<<(num1/num2)<<endl;
            break;
        case's':
            cout<<"The swap of two numbers ("<<num1<<","<<num2<<"):";
            swap(num1,num2);
            cout<<"1stnumber="<<num1<<"and 2nd number="<<num2<<endl<<endl;
            break;
        default:
            cout<<"unknown command"<<endl;

        }
        //----now once again the program will ask the user if want to continue or not
        cout<<"enter y or Y to continue:";
        cin>>redo;
        cout<<endl<<endl;
    }
    while(redo=='y'||redo=='Y');

    return 0;

}


/*
 * OutPut >>
Welcome to the calculater program v.1.0 written by Your Name
***************************************************************



 Please enter an operation which you like to calculate (+,-,*,/,s)[s stands for swap]:+


 Please enter two numbers to apply your requested operation(+):
1st num:66
2nd num:77

The addition of two numbers (66,77):143
enter y or Y to continue:
*/