Simple Example Program for Passing pointers to functions In C++


Pass By Reference Definition

  • Each parameter was followed by an ampersand sign (&). (&) will pass an address of the original variable instead of by value.
  • In Passed by reference, the original variable and the function variable use the same memory/variable for the parameter. If the function variable modifies the parameter value, the effect is visible to the original variable.

Syntax

//Function - Pass By Reference
void fn_name(int *var1,int *var2)
{
   // Code
}

//Main Code- Pass By Reference
fn_name(&orginal_var1,&orginal_var2);

Simple Example Program for Passing pointers to functions

/*##Simple Example Program for Passing pointers to functions In C++*/
/*##Simple Add Numbers C++ Programs,pointers Example C++ Programming*/
/*##Pass By Reference Function C++ Example Program In C++ Programming*/

// Header Files
#include <iostream>
#include<conio.h>

using namespace std;

// Declare Add Numbers Function Using Pointer 

void add_numbers(int *value1, int *value2, int *result) {
   *result = *value1 + *value2;
}

int main() {
   // Declare Variables
   int number1, number2, result = 0;

   cout << "Pointer Example C++ Program : Passing pointers to functions In C++ \n";

   // Read User Input
   cout << "Enter value of Number # 1: ";
   cin>>number1;
   cout << "Enter value of Number # 2: ";
   cin>>number2;

   //Print Values Pass to Reference
   cout << "Before Pass to Reference :  Number # 1=" << number1 << ",  Number # 2=" << number2 << ", Result # :" << result << " \n";

   //Call add_numbers Function By Passing Reference
   add_numbers(&number1, &number2, &result);

   //Print Values Pass to Reference
   cout << "After  Pass to Reference :  Number # 1=" << number1 << ",  Number # 2=" << number2 << ", Result # :" << result << "\n";

   getch();
   return 0;
}

Sample Output

Pointer Example C++ Program : Passing pointers to functions In C++
Enter value of Number # 1: 100
Enter value of Number # 2: 200
Before Pass to Reference :  Number # 1=100,  Number # 2=200, Result # :0
After  Pass to Reference :  Number # 1=100,  Number # 2=200, Result # :300