C++ program to find reverse of a number

In this chapter of C++ program tutorial out task is: 

• Write a C++ program to find the reverse of the number.

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C++ program to find the reverse of the number

Below is the C++ program to find reverse of the number.

#include<iostream>
using namespace std;
int main()
{
    int number;
    cout<<"Enter the number:"<<endl;
    cin>>number;
    int reverseNumber=0,remainder;
    while(number!=0){
        remainder = number % 10;
        reverseNumber = reverseNumber * 10 + remainder;
        number = number / 10;
    }
    cout<<"The reverse of the given number is"<<" "<<reverseNumber<<endl;
    return 0;
}

OUTPUT :

Enter the number:

• The execution starts from the main function (here int main()).
• A 4 bit memory space is created for each of the integers 'number','reverseNumber ','remainder'(assuming 64 bit system).
• The 'reverseNumber' variable is assigned with value 0 initially or it will take garbage value and give undesired output.
• In the while statement it is checking that it will run the loop untill the number becomes 0.
• In the 'remainder' variable it is extracting the last digit and storing it in the 'reverseNumber' as the first digit.
• Then that digit is removed from the 'number' variable and the loop continues.
• Then the reverse of the number is given as the output.
• The program than gives the desired output and terminates in the line "return 0" returning a 0 value.

WORKING :

number = 1678

while(1678!=0)

{

remainder = 1678 % 10       // remainder  = 8

reverseNumber = 0 * 10 + 8    //reverseNumber = 8

number = 1678 / 10    // number = 167

}

next loop :

number = 167

while(167!=0)

{

remainder = 167 % 10       // remainder  = 7

reverseNumber = 8 * 10 + 7    //reverseNumber = 87

number = 167 / 10    // number = 16

}

next loop :

number = 16

while(16!=0)

{

remainder = 16 % 10       // remainder  = 6

reverseNumber = 87 * 10 + 6    //reverseNumber = 876

number = 16 / 10    // number = 1

}

next loop :

number = 1

while(1!=0)

{

remainder = 1 % 10       // remainder  = 1

reverseNumber = 876 * 10 + 1    //reverseNumber = 8761

number = 1 / 10    // number = 0

}

The loop terminates as the number becomes 0 

 

You can see the above code execution and output in codeblocks IDE: