C# String IsNullOrEmpty() Method

// C# program to demonstrate the use of  
// String.IsNullOrEmpty() method  
using System;  
class Geeks  
{  
    static void Main(string[] args)  
    {   
        // Empty String  
        string s1 = "";  
        // Non-Empty String  
        string s2 = "Geek";  
        // Check for null or empty string  
        bool res = String.IsNullOrEmpty(s1);  
        // Display the result  
        Console.WriteLine($"\"{s1}\" is null or empty: {res}");  
        res = String.IsNullOrEmpty(s2);  
        // Display the result  
        Console.WriteLine($"\"{s2}\" is null or empty: {res}");  
    }  
}  

// C# program to illustrate an  
// alternative method for IsNullOrEmpty()  
using System;  
class Geeks  
{  
    // Custom method similar to IsNullOrEmpty()  
    public static bool Check(string s)  
    {  
        return s == null || s == String.Empty; // Equivalent to IsNullOrEmpty()  
    }  
    // Main Method  
    public static void Main(string[] args)  
    {  
        string s1 = "GeeksforGeeks";  
        // Declare an empty string  
        string s2 = "";  
        // Declare a null string  
        string s3 = null;  
        bool b1 = Check(s1);  
        bool b2 = Check(s2);  
        bool b3 = Check(s3);  
        // Display the result  
        Console.WriteLine(b1);  
        Console.WriteLine(b2);  
        Console.WriteLine(b3);  
    }  
}