C++ Program to Swap Two Numbers

In this tutorial, we will learn about the swapping of numbers in C++ i.e. how to write a program to swap two numbers using C++.

Quick Info:💡

↪ Swapping of two numbers means exchange the values of two variables with each other.

↪ For example, suppose you have a two numbers var1=45 and var2=50 then, after swapping numbers will become var1=50 and var2=45.

↪ Here’s the following steps to swap the number:

  • First, consider any two digits number.
  • Second, assign the first value to the second variable.
  • Third, assign the second value to the first variable.

↪ Here’s the two methods to perform the swapping of two numbers:

  • Without using third variable
  • With using third variable

Program to Swap Two Numbers Without Using Third Variable

Swapping of two numbers without using a third variable(i.e. temporary variable) is the simplest way to swap the numbers.

Steps to perform above task:

  • Initially, take two variables (a and b).
  • Second, add two variables and store it in the first variable(i.e. a).
  • Third, subtract two variables and store it in a second variable(i.e. b).
  • Again, subtract two variables and store it in the first variable(i.e. a)

Example:

#include<iostream.h>
#include<conio.h>
void main()
{
int first_number, second_number;
cout<<"Enter first number";
cin>>first_number;
cout<<"Enter second number";
cin>>second_number;
first_number=first_number+second_number;
second_number=first_number-second_number;
first_number=first_number-second_number;
cout<<"Numbers after swapping:="<<endl;
cout<<"First number after swapping: "<<first_number<<endl;
cout<<"Second number after swapping: "<<second_number<<endl;
getch();
}
//Output:
Enter first number 34
Enter second number 67
Numbers after swapping:=
First number after swapping: 67
Second number after swapping: 34
swap_without_temp

Working:

Flow of the program:

swap_without_temp_working

Program to Swap Two Numbers Using Third Variable

Another way to swap two numbers is using a temporary variable as a third variable.

Steps to perform above tasks:

  • User is asked to enter the values (a and b).
  • Assign the value of the first variable to the temporary variable.
  • Assign the value of the second variable to the first variable.
  • Assign the value of the third variable to the second variable.

Example:

#include<iostream.h>
#include<conio.h>
void main()
{
int first_number, second_number, temp;
cout<<"Enter first number";
cin>>first_number;
cout<<"Enter second number";
cin>>second_number;
temp=first_number;
first_number=second_number;
second_number=temp;
cout<<"Numbers after swapping are:="<<endl;
cout<<"First number after swapping: "<<first_number<<endl;
cout<<"Second number after swapping: "<<second_number;
getch();
}
//Output:
Enter first number 34
Enter second number 67
Numbers after swapping are:=
First number after swapping: 67
Second number after swapping: 34
swap_with_temp

Working:

Flow of the program:

swap_with_temp_working

Wrapping Up:

From the above examples, we understood that there are several ways to write a single program using different ways.

Sounds Interesting! Right?

Well, I hope it really helped you to know the C++ better.

And, if you liked this stay with us to get more such exciting codes to explore more in C++.

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