C# String IsNullOrEmpty() Method

In C#, IsNullOrEmpty() is a string method. It is used to check whether the specified string is null or an Empty string. A string will be null if it has not been assigned a value. A string will be empty if it is assigned “” or String.Empty (A constant for empty strings).

Example 1: Using IsNullOrEmpty() to check whether the string is Null or empty.

"" is null or empty: True
"Geek" is null or empty: False

Syntax:

public static bool IsNullOrEmpty(String str)

• Parameter: It takes a single parameter str, which is of type System.String
• Return-Type: Returns a boolean value. If the str parameter is null or an empty string (“”) then return True otherwise return False.

Note: The IsNullOrEmpty method is used to check whether a string is either null or empty ("").
A simple alternative to IsNullOrEmpty() can be written as:

return s == null || s == String.Empty;

This alternative works similarly but lacks the built-in optimization and clarity of IsNullOrEmpty().

Example 2: Demonstrating a similar method to IsNullOrEmpty() and its internal workings.