Why do we pass a Pointer by Reference in C++?

If we need to modify a pointer rather than the object that the pointer is pointing to, we pass a pointer by reference.

Here is an example of how to pass a pointer by reference −

Example

 Live Demo

#include <iostream>
using namespace std;
void Decrement( int*& d ) {
   --d;
}
int main( void ) {
   int a = 26;
   int* ptr = &a; // pointer to pass
   // print before decrement
   cout<<"Before: "<< ptr << endl;
   Decrement( ptr);
   // print after increment
   cout<<"After: " << ptr;
   return 0;
}

Output

Before: 0x6ffe3c
After: 0x6ffe38

Anvi Jain

Published on 18-Jun-2019 12:33:19

• Related Questions & Answers
• How do we pass parameters by reference in a C# method?
• Differences between pass by value and pass by reference in C++
• Pass by reference vs Pass by Value in java
• Passing by pointer Vs Passing by Reference in C++
• Why do we check for a NULL pointer before deleting in C/C++?
• Is java pass by reference or pass by value?
• Is JavaScript a pass-by-reference or pass-by-value language?
• How do you pass objects by reference in PHP 5?
• Describe pass by value and pass by reference in JavaScript?
• How do we pass parameters by value in a C# method?
• What is pass by reference in C language?
• What is Pass By Reference and Pass By Value in PHP?
• How to pass an array by reference in C++
• Which one is better in between pass by value or pass by reference in C++?
• Pass an integer by reference in Java