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Calculate the Number of Digits in a Positive Integer (Handling Negative Input) in C#

In this C# program, the user will be prompted to enter an integer. The program will calculate and display the number of digits in that integer. The key approach here is repeatedly dividing the number by 10 to extract each digit and counting how many times this division is possible.

To address the requirement for handling negative integers, the program will check if the entered number is negative. If it is, a warning message will be displayed, and the program will proceed by converting the negative number to its absolute value before performing the digit count.

This type of problem can be useful in situations where you need to validate or manipulate numbers based on their size, especially when working with user inputs. The approach leverages a simple mathematical technique to break down the problem and achieve the desired result.



Group

C# Flow Control Basics

Objective

Write a C# program to calculate the number of digits in a positive integer (hint: this can be done by repeatedly dividing by 10). If the user enters a negative integer, the program should display a warning message and proceed to calculate the number of digits for the equivalent positive integer.

For example:
Number = 32
2 digits
Number = -4000
(Warning: it is a negative number) 4 digits

Example C# Exercise

 Copy C# Code 
using System;

namespace CountDigits
{
    class Program
    {
        static void Main(string[] args)
        {
            // Prompt the user to enter a number
            Console.Write("Enter a number: ");
            int number = int.Parse(Console.ReadLine()); // Read the input number

            // Check if the number is negative
            if (number < 0)
            {
                Console.WriteLine("(Warning: it is a negative number)"); // Display a warning for negative numbers
                number = Math.Abs(number); // Convert the negative number to positive by using Math.Abs
            }

            // Initialize a counter for the number of digits
            int digitCount = 0;

            // Check if the number is 0, as it has exactly one digit
            if (number == 0)
            {
                digitCount = 1; // The number 0 has one digit
            }
            else
            {
                // Loop to divide the number by 10 until it becomes 0
                while (number > 0)
                {
                    number /= 10; // Divide the number by 10 in each iteration
                    digitCount++; // Increment the digit count
                }
            }

            // Display the result
            Console.WriteLine($"The number has {digitCount} digits.");
        }
    }
}

 Output

Enter a number: 32
The number has 2 digits.

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