Reverse Number Program in C

This C program reverses an integer entered by the user.

It uses a while loop to extract each digit from the input number, appending them in reverse order to form the reversed number.

Algorithm Steps   

Declare variables:

number: to store the input number.

reversed number: to store the reversed number.

remainder: to capture the last digit of the number.

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Input:

Prompt the user to enter an integer using printf and read it with scanf.

Reverse the Number:

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Iterate using a while loop:

Calculate the remainder as the last digit of the number.

Update the reversed number by appending the remainder.

Reduce the number by one digit by dividing it by 10.

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Output:

Display the reversed number using printf.

Example:

// program for reversed Number in C
#include<stdio.h> 

int main() {
    int number, reversedNumber = 0, remainder;

    // Input
    printf("Enter an integer: ");
    scanf("%d", &number);

    // Reverse the number
    while (number != 0) {
        remainder = number % 10;        // Extract the last digit
        reversedNumber = reversedNumber * 10 + remainder;  // Append the digit
        number /= 10;                   // Remove the last digit
    }

    // Output
    printf("Reversed number: %d\n", reversedNumber);

    return 0;
}

Output:

Reversed number: 987

Execution:

If the user enters 7890, the program will output:

Reversed number: 987

This confirms that the number 7890 has been reversed to 987.