# C++ PROGRAM TO REVERSE THE NUMBER!!!

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|LOGIC OF REVERSING THE NUMBER|

In this program, we are getting numbers as input from the user and reversing that number.

- Let’s start the program with a header file.

“** “#include<iostream>” →**Input-output continuous bytes of data.

** “using namespace std;” **→used to store variable name.

** “int main()”** →returns datatype function.”

*“{*

*int n, reverse=0, rem;*

*cout<<” Enter a number: “;*

*cin>>n;”*

- Let us declare the variable in integer form (n, reverse=0, rem) because we going to enter numbers; In
, we have given enter a number.*“cout statement”*

cout →character output.

cin →character input.

*“while(n>0)*

*{rem=n%10;*

*reverse=reverse*10+rem;*

*n/=10;}”*

## LOGIC OF THE CODE:

# Step 1 — Isolate the last digit in number

`lastDigit = number % 10`

The modulo operator (%) returns the remainder of a division. In this case, we divide the **number** by 10 and return the remainder. Consider the integer **1234**. The *tens* column (30) is divided by 10 without remainder, the *hundreds* column (200) as well, and also the *thousands* column (1000). The remainder of the division will be **4 **representing the *ones* column that could not be divided by 10. We now have the means to isolate the last digit of any integer. We save this in the variable the **last digit**.

# Step 2 — Append the last digit to reverse

`reverse = (reverse * 10) + lastDigit`

We can start building the reversed number now by appending **last digit** onto the end of a **reverse**. Remember that both of these variables are integers so we can not simply concatenate. We **multiply reverse by 10** so that the *ones* column becomes the *tens* column, the *tens* column becomes the *hundreds* column, and so on. This also leaves us with a new *ones* column where we can add our last digit** **which we determined was **4** in our example.

reverse = (0 * 10) + 4

reverse = 4

We have successfully copied the last digit of the **number** and appended it to **reverse**.

# Step 3-Remove last digit from the number

`number = number / 10`

Notice that **number** is still 1234, even though we have already used that 4 on the end. To remove the last digit from a **number** we simply divide it by 10. This works because we are performing integer division which rounds results down to the nearest integer (ex. 244 / 10 = 24).

# Step 4-Iterate this process

`while (number > 0)`

Repeat this process until a **number** is reduced to zero and the **reverse** is completed.

*“cout<<” Reversed Number: “<<reverse<<endl;*

*return 0;}”*

It will reverse a number in output because we have given reverse number in *“cout statement”*

endl →avoid buffer statement and display in new line.

return 0 →that means the program is executed successfully.reverse number.