Here is my functions based calculator in C++.

@miguel

any suggestions!!

```
/*
This is a multi-all-in-one function calling program.
in this program the user will be able to call different
programs using if else statments.
*/
#include <iostream>
using namespace std;
// this is the addition function.
int addition (int a, int b)
{
int adding_operation;
adding_operation = a + b;
return adding_operation;
}
//this is the subtraction function.
int subtraction (int c, int d)
{
int subtraction_operation;
subtraction_operation = c - d;
return subtraction_operation;
}
//this is the multiplication function.
int multiplication (int e, int f)
{
int multiplication_operation;
multiplication_operation = e * f;
return multiplication_operation;
}
//this is the division function.
int division (int g, int h)
{
int division_operation;
division_operation = g / h;
return division_operation;
}
//this is the remainder function.
int remainder (int i, int j)
{
int remainder_operation;
remainder_operation = i % j;
return remainder_operation;
}
int main()
{
//this is the conditions part of the program.
char op;
int x;
int y;
cout<<" input operation type: (avilable types are +, -, *, /, %)"<<endl;
cin>>op;
cout<<"enter the first value (any integer number)"<<endl;
cin>>x;
cout<<"enter the second value (any integer number)"<<endl;
cin>>y;
//this is the apply condition section of the program.
switch(op){
case '+':
int excute_addition;
excute_addition = addition(x, y);
cout<<"The result is:" << excute_addition << '\n';
break;
case '-':
int excute_subtraction;
excute_subtraction = subtraction(x, y);
cout<<"The result is:" << excute_subtraction << '\n';
break;
case '*':
int excute_multiplication;
excute_multiplication = multiplication(x, y);
cout<<"The result is:" << excute_multiplication << '\n';
break;
case '/':
int excute_division;
excute_division = division(x, y);
cout<<"The result is:" << excute_division << '\n';
break;
case '%':
int excute_remainder;
excute_remainder = remainder(x, y);
cout<<"The result is:" << excute_remainder << '\n';
break;
default:
cout<<"invaled operation"<< '\n' <<endl;
break;
}
//looping the program;
int user_decision;
cout<<"Would you like to run the program again? (1 for yes, 2 for no)"<<endl;
cin>>user_decision;
if ( user_decision == 1 ){
return main();
}else if( user_decision == 2 ){
return 0;
}
}
```