C# Program: Convert user input string to integer with exception handling

C# Sharp Exception Handling: Exercise-6 with Solution

Write a C# program that reads a string from the user and converts it to an integer. Handle the exception if the input cannot be parsed into an integer.

Sample Solution:

C# Sharp Code:

using System;

class Program {
  static void Main() {
    try {
      // Prompt the user to input a number
      Console.Write("Input a number: ");
      string input = Console.ReadLine();

      // Attempt to convert the user input to an integer
      int number = ConvertToInt(input);

      // Display the converted number
      Console.WriteLine("Number: " + number);
    } catch (FormatException) {
      // Catch block for handling FormatException when non-integer input is entered
      Console.WriteLine("Error: Invalid input. Please enter a valid integer.");
    } catch (Exception ex) {
      // Catch block for handling other types of exceptions
      Console.WriteLine("An error occurred: " + ex.Message);
    }
  }

  // Method to convert string input to an integer
  static int ConvertToInt(string input) {
    return int.Parse(input); // Convert string to integer
  }
}

Sample Output:

Input a number: abc
Error: Invalid input. Please enter a valid integer.

 
Input a number: 123
Number: 123

Explanation:

In the above exercise,

• The "Main()" method prompts the user to input a number as a string using Console.Write() and Console.ReadLine(). The input is stored in the input variable.
• The program calls the ConvertToInt method, passing the input string as an argument.
• The ConvertToInt method uses int.Parse to convert the string to an integer. If the input cannot be parsed, a FormatException is thrown.
• In the "Main()" method, the exceptions are handled using catch blocks. If a FormatException occurs, it means the input was not a valid integer. The program catches this exception and displays an appropriate error message.
• Any other exceptions are caught by the generic catch block, and a general error message is displayed.

Flowchart:

C# Sharp Code Editor:

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