C++ program to view the difference between pass by value, pass by reference, return by reference

#include<iostream.h>
#include<conio.h>
class cpp
{

	public:
		void call_by_value(int,int);
		void call_by_reference(int*,int*);
		int & return_by_reference(int &,int &);
		void ref(int &,int &);

};
	int & cpp::return_by_reference(int &x,int &y)
	{
		if(x>y)
		return x;
		else
		return y;
	}
	void cpp::ref(int &x,int &y)
	{
		int t;
		t=x;
		x=y;
		y=t;
		cout<<"\na is:"<<x<<"\tb is:"<<y;
	}
	void cpp::call_by_value(int x,int y)
	{
		int t;
		t=x;
		x=y;
		y=t;
		cout<<"\nvalue of a="<<x<<"\nvalue of b="<<y;
	}
	void cpp::call_by_reference(int *x,int *y)
	{
		int *t;
		*t=*x;
		*x=*y;
		*y=*t;
		cout<<"\nvalue of a="<<*x<<"\nvalue of b="<<*y;
	}


	void main()
	{
	cpp r;
	int k,c,a,b;
	clrscr();
	do
	{
		cout<<"\n*********************************************\n";
		cout.width(30);
		cout<<"PASSING ARGUMENTS\n";
		cout<<"***********************************************\n";
		cout<<"1.pass by value\n";
		cout<<"2.pass by reference\n";
		cout<<"3.return by reference\n";
		cout<<"4.ref\n5.exit";
		cout<<"***********************************************\n";

		cout<<"Enter u r choice";
		cin>>k;
		switch(k)
		{
			case 1:
				cout<<"\nEnter a and b";
				cin>>a>>b;

				r.call_by_value(a,b);
				break;
			case 2:

				cout<<"\nEnter a and b";
				cin>>a>>b;
				r.call_by_reference(&a,&b);
				break;
			case 3:
				cout<<"\nEnter a and b";
				cin>>a>>b;
				c=r.return_by_reference(a,b);
				cout<<"\nMaximum value"<<c;
				break;
			case 4:
				cout<<"\nenter a,b:";
				cin>>a>>b;
				r.ref(a,b);
		}
	}while(k!=5);
	getch();
	}

Categories: C++ Programming, CPP