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Check if a String is an Integer in C#

This C# function is designed to check if a given string represents an integer number. The function should return a boolean value indicating whether the string can be successfully parsed as an integer. This is useful for validating user input or processing data where you need to ensure that a string contains a valid integer. For example, if the input is "1234", the function should return true, and the program should output "It is a numerical value".



Group

Functions in C#

Objective

1. Write a function named "IsNumber" that takes a string as a parameter.
2. The function should attempt to parse the string to an integer using the `int.TryParse()` method.
3. If the string can be parsed successfully as an integer, return true; otherwise, return false.
4. Use the function in a sample program that checks whether a string represents a valid integer and outputs an appropriate message.

Write a C# function that tells if a string is an integer number. It should be used like this:

if (IsNumber ("1234"))
System.Console.WriteLine ("It is a numerical value");

Example C# Exercise

 Copy C# Code 
using System;

class Program
{
    // Function to check if a string is a valid integer
    public static bool IsNumber(string input)
    {
        // Try to parse the input string as an integer
        return int.TryParse(input, out int result);
    }

    // Main method to test the IsNumber function
    public static void Main(string[] args)
    {
        // Test with a sample string
        string testString = "1234";

        // Check if the string is a valid integer
        if (IsNumber(testString))
        {
            // Output if the string is a valid integer
            System.Console.WriteLine("It is a numerical value");
        }
        else
        {
            // Output if the string is not a valid integer
            System.Console.WriteLine("It is not a numerical value");
        }
    }
}

 Output

It is a numerical value

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