C# String IsNullOrEmpty() Method Last Updated : 25 Mar, 2025 Comments Improve Suggest changes Like Article Like Report 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. C# // 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}"); } } Output"" 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. C# // 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); } } OutputFalse True True Comment More infoAdvertise with us Next Article Company-wise Practice Problems M Mithun Kumar Follow Improve Article Tags : C# CSharp-method CSharp-string Similar Reads Interview PreparationInterview Preparation For Software DevelopersMust Coding Questions - Company-wise Must Do Coding Questions - Topic-wiseCompany-wise Practice ProblemsCompany PreparationCompetitive ProgrammingSoftware Design-PatternsCompany-wise Interview ExperienceExperienced - Interview ExperiencesInternship - Interview ExperiencesPractice @GeeksforgeeksProblem of the DayTopic-wise PracticeDifficulty Level - SchoolDifficulty Level - BasicDifficulty Level - EasyDifficulty Level - MediumDifficulty Level - HardLeaderboard !!Explore More...Data StructuresArraysLinked ListStackQueueBinary TreeBinary Search TreeHeapHashingGraphAdvance Data StructuresMatrixStringAll Data StructuresAlgorithmsAnalysis of AlgorithmsSearching AlgorithmsSorting AlgorithmsPattern SearchingGeometric AlgorithmsMathematical AlgorithmsRandomized AlgorithmsGreedy AlgorithmsDynamic ProgrammingDivide & ConquerBacktrackingBranch & BoundAll AlgorithmsProgramming LanguagesCC++JavaPythonC#Go LangSQLPHPScalaPerlKotlinWeb TechnologiesHTMLCSSJavaScriptBootstrapTailwind CSSAngularJSReactJSjQueryNodeJSPHPWeb DesignWeb BrowserFile FormatsComputer Science SubjectsOperating SystemsDBMSComputer NetworkComputer Organization & ArchitectureTOCCompiler DesignDigital Elec. & Logic DesignSoftware EngineeringEngineering MathematicsData Science & MLComplete Data Science CourseData Science TutorialMachine Learning TutorialDeep Learning TutorialNLP TutorialMachine Learning ProjectsData Analysis TutorialTutorial LibraryPython TutorialDjango TutorialPandas TutorialKivy TutorialTkinter TutorialOpenCV TutorialSelenium TutorialGATE CSGATE CS NotesGate CornerPrevious Year GATE PapersLast Minute Notes (LMNs)Important Topic For GATE CSGATE CoursePrevious Year Paper: CS exams Like