Passing Arguments in C++

Passing Arguments

This example demonstrates different techniques of passing arguments: by value, by reference, and as pointers
Source File

#include void main(){ int Boys = 3, Girls = 5; void PassByValue(int males, int females); void Reference(int &m, int &f); void Pointers(int *u, int *v); cout << "At startup, within main()"; cout << "\n\tBoys = " << Boys; cout << "\n\tGirls = " << Girls; cout << "\nPassing arguments by value = Copy"; PassByValue(Boys, Girls); cout << "\nAfter calling PassByValue(), within main()"; cout << "\n\tBoys = " << Boys; cout << "\n\tGirls = " << Girls; cout << "\nPassing arguments by reference"; Reference(Boys, Girls); cout << "\nAfter calling Reference(), within main()"; cout << "\n\tBoys = " << Boys; cout << "\n\tGirls = " << Girls; cout << "\nPassing arguments pointers"; Pointers(&Boys, &Girls); cout << "\nAfter calling Pointers(), within main()"; cout << "\n\tBoys = " << Boys; cout << "\n\tGirls = " << Girls; cout << "\n";}void PassByValue(int b, int g){ b += 3, g += 4; cout << "\nWithin PassByValue(), now"; cout << "\n\tBoys = " << b; cout << "\n\tGirls = " << g;}void Reference(int &b, int &g){ b = b + 8, g = g + 5; cout << "\nWithin Reference(), now"; cout << "\n\tBoys = " << b; cout << "\n\tGirls = " << g;}void Pointers(int *b, int *g){ *b = 44, *g = 52; cout << "\nWithin Pointers(), now"; cout << "\n\tBoys = " << *b; cout << "\n\tGirls = " << *g;}

This would produce:


At startup, within main() Boys = 3 Girls = 5Passing arguments by value = CopyWithin PassByValue(), now Boys = 6 Girls = 9After calling PassByValue(), within main() Boys = 3 Girls = 5Passing arguments by referenceWithin Reference(), now Boys = 11 Girls = 10After calling Reference(), within main() Boys = 11 Girls = 10Passing arguments pointersWithin Pointers(), now Boys = 44 Girls = 52After calling Pointers(), within main() Boys = 44 Girls = 52