Function parameters

[y05iz8AR]

How to pass a functions as a parameter and use the values in it?

I am trying to develop a billing system, i have about 12 function. 1 function for each food type there are six food types and other are like search, about us etc functions., I have calculated the price and the quantity need in the food functions. I want to pass it to the invoice function. There are lot of data I want to pass like the item code, unit price, quantity, item name etc in one function. Since there are 6 functions it is difficult to do that so. Is it possible to pass a function as a parameter and take all the necessary values from it.

[martianxx]

You can use functions as arguments for another function such as:

int calcArea();
void DisplayArea(int area);

int main ()
{
   DisplayArea(CalcArea());
}

However the way you have explained you are doing it seems very un necessary. You could have a single function for all the different types of food by creating some variable that reprents food type (such as an enumerator). This would mean you no longer need 6 function for 6 types of food. Even if you managed to get it to work your program would not be very scalabe. Think of a massive version of your program that people use all the time (like an online ordering system) it wouldnt be very scalable to have a function for each type of food. If you want more help you are going to have to explain your problem more and give code for us to read.

[toum]

@aazir : Use a structure in which you'll pack all your data.

@martianxx : Your example has nothing to do with passing functions as arguments. You're passing the return value of a function, which is a completely different thing.

[martianxx]

Sorry I thought the return value was what he wanted. If you want to pass the actual function then you do it in the following way by passing a pointer to the function.

#include <iostream>

using namespace std;

void DoSomething(void (f*)(void));
void HelloWorld();

int main()
{
   DoSomething(HelloWorld);
   return 0;
}
void DoSomething(void (f*)(void))
{
   (*f)();
}
void HelloWorld()
{
   cout << "Hello World" << endl;
}

As said using structures would significantly reduce the complexity. Plus you can pass the structure instance like any other variable type.

[y05iz8AR]

Thank You!!!