# Swapping of Two Numbers in C++ Using Functions | Call by Value

Swapping of Two Numbers in C++ Using Functions Call by Reference and Call by Value. There are two methods to solve this problem with the help of functions. The first one is Call By Value and the second one is Call by Reference. In the Call by Value Function, we can pass the value and in the Call by Reference Function we pass the Address of the variable. Before going diving into the Call by Reference and Call by Value.

There are 2 things we have to discuss Actual Parameter and the Formal Parameter to fully understand the Swapping of Two Numbers in C++ Using Functions. Swapping of two numbers in this article I am going to explain Call By Value, Call by Reference, Actual Parameter and Formal Parameter. So all the doubts will be clear to understand this problem.

Check This: C++ Program to Calculate Standard Deviation Using Function

## Swapping of Two Numbers in C++ Using Functions | Call by Reference

``````#include<iostream>
using namespace std;

void swap(int *x ,int *y );
/*Swapping of Two Numbers in C++ Using Functions Call by Reference*/
int main()
{
int a,b;
cout<<"Enter Two Numbers To Swap: ";
cin>>a>>b;

swap(&a,&b);

cout<<"\nAfter Swapping Two Numbers: ";
cout<<a<<" "<<b<<" \n";

return 0;
}
void swap(int *x,int *y)
{
int z;
z=*x;
/*Copying the first variable Address to the tempriory variable*/
*x=*y;
/*Copying the second variable Address to the first variable*/
*y=z;
/*Copying the tempriory variable Address to the second variable*/
}``````

### Swapping of Two Numbers in C++ Using Call by Value Functions

``````#include<iostream>
using namespace std;

void swap(int ,int );
/*Swapping of Two Numbers in C++ Using Functions Call by Value*/
int main()
{
int a,b;
cout<<"Enter the Two Numbers to Swap in C++: ";
cin>>a>>b;
cout<<"\nAfter Swapping of Two Numbers:";
swap(a,b);

return 0;
}
void swap(int x,int y)
{
int z;
/*Extra veriable for storing the value of first or second variable*/

z=x;
/*Copying the first variable value to the tempriory variable*/
x=y;
/*Copying the second variable value to the first variable*/
y=z;
/*Copying the tempriory variable value to the second variable*/
cout<<" "<<x<<"   "<<y;

}``````

### Swapping of Two Numbers Using Function Call by Reference & Call by Value

#### 1. Call by Value

In Call by Value Actual parameters are passed while calling the function, The operation's effect on the formal parameters doesn't reflect on the Actual Parameters.

Example: Int A = 5 is an actual parameter and Int X = 5(Here we have Copied the Int A = 5 value to the X = 5), so whatever we do with the X, it does not reflect the Actual Value Int A = 5. It will always remain the same. If we increase the value of the X by 1 then the value of the X will be 6 and the value of the A remains the same as 5 as previously.

#### 2. Call by Reference

In Call by Reference, we passed the address of the actual parameter in a formal parameter, So the changes on the Formal Parameters reflect on the Actual parameters. If we take the above example for this then if we increase the value of the X will reflect on the A thus the value of the X and A will be the same(X = A = 6)

Before going to understand the Call by value and Call by Reference let's first understand the Actual and Formal Parameters terminology to fully understand the code.

Actual Parameters: The Actual parameters that appear in function calls.
Formal Parameters: The Formal parameters that appear in function declarations.

### The Output of Swapping of Two Numbers in C++ Using Call by Value

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#### post written by: Ghanendra Yadav

Hi, I’m Ghanendra Yadav, SEO Expert, Professional Blogger, Programmer, and UI Developer. Get a Solution of More Than 500+ Programming Problems, and Practice All Programs in C, C++, and Java Languages. Get a Competitive Website Solution also Ie. Hackerrank Solutions and Geeksforgeeks Solutions. If You Are Interested to Learn a C Programming Language and You Don't Have Experience in Any Programming, You Should Start with a C Programming Language, Read: List of Format Specifiers in C.