Check if a String Is Null or Empty in C#

  1. Check if a String Is Empty or Null in C
  2. Check if a String Is Null in C
  3. Check if a String Variable Is Empty in C

This tutorial will discuss the methods of checking if a string is empty or null in C#.

Check if a String Is Empty or Null in C

If we want to check for a string that has either null value or "" value in it, we can use the string.IsNullOrEmpty() method in C#. The string.IsNullOrEmpty() method has a boolean return type. It returns true if the string is either empty or null. See the following code example.

using System;

namespace check_string
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = null;
            if (string.IsNullOrEmpty(s))
            {
                Console.WriteLine("String is either null or empty");
            }
        }
    }
}

Output:

String is either null or empty

In the above code, we assigned the null value to the string variable s and check whether it is empty or null with the string.IsNullOrEmpty() method in C#.

Check if a String Is Null in C

In the above section, we check for the null value and "" value combined. If we want to separately check whether a string is null or not, we can use the == comparison operator. See the following code example.

using System;

namespace check_string
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = null;
            if(s == null)
            {
                Console.WriteLine("String is null");
            }
        }
    }
}

Output:

String is null

In the above code, we check whether the string variable s is null or not with the == comparison operator in C#.

Check if a String Variable Is Empty in C

As in the previous example, we can also separately check whether a string is empty or not with the string.Empty field in C#. The string.Empty field represents an empty in C#. See the following code example.

using System;

namespace check_string
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = "";
            if(s == string.Empty)
            {
                Console.WriteLine("String is empty");
            }
        }
    }
}

Output:

String is empty

In the above code, we check whether the string is empty with the string.Empty field in C#.

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