C# | Random.NextBytes() Method Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The NextBytes(Byte[]) method of the System.Random class in C# is used to fill the elements of a specified array of bytes with random numbers. This method takes a byte array as a parameter and fills it with random numbers. Syntax: public virtual void NextBytes (byte[] buffer); Here, buffer is the array of bytes to contain random numbers. Exception: This method will give ArgumentNullException if the buffer is null. Below programs illustrates the use of NextBytes() method: Example 1: csharp // C# program to illustrate the // use of Random.NextBytes Method using System; class GFG { // Driver code public static void Main() { // Instantiate random number generator Random rand = new Random(); // Instantiate an array of byte Byte[] b = new Byte[10]; rand.NextBytes(b); // Print random numbers in the byte array Console.WriteLine("Printing random numbers"+ " in the byte array"); for (int i = 0; i < 10; i++) Console.WriteLine("{0} -> {1}", i, b[i]); } } Output: Printing random numbers in the byte array 0 -> 63 1 -> 166 2 -> 5 3 -> 212 4 -> 114 5 -> 94 6 -> 161 7 -> 4 8 -> 226 9 -> 46 Example 2: csharp // C# program to illustrate the // use of Random.NextBytes Method using System; class GFG { // Driver code public static void Main() { // Instantiate random number generator Random rand = new Random(); // Instantiate an array of byte Byte[] b = new Byte[10]; rand.NextBytes(b); // Print random numbers in the byte array Console.WriteLine("Printing random numbers"+ " in the byte array"); foreach(byte byteValue in b) Console.WriteLine("{0}", byteValue); } } Output: Printing random numbers in the byte array 98 68 221 160 179 78 172 129 121 179 Reference: https://learn.microsoft.com/en-us/dotnet/api/system.random.nextbytes?view=netframework-4.7.2 Create Quiz Comment R rupesh_rao Follow 0 Improve R rupesh_rao Follow 0 Improve Article Tags : C# CSharp-method CSharp-Random-Class Explore IntroductionC# Tutorial 2 min read Introduction to .NET Framework 6 min read C# .NET Framework (Basic Architecture and Component Stack) 6 min read C# Hello World 2 min read Common Language Runtime (CLR) in C# 4 min read FundamentalsC# Identifiers 2 min read Data Types in C# 6 min read C# Variables 4 min read C# Literals 5 min read Operators in C# 7 min read C# Keywords 5 min read Control StatementsC# Decision Making (if, if-else, if-else-if ladder, nested if, switch, nested switch) 5 min read C# Switch Statement 4 min read Loops in C# 4 min read C# Jump Statements (Break, Continue, Goto, Return and Throw) 4 min read OOP ConceptsClass and Objects in C# 4 min read Constructors in C# 5 min read C# Inheritance 3 min read Encapsulation in C# 2 min read C# Abstraction 4 min read MethodsMethods in C# 4 min read Method Overloading in C# 4 min read Method Parameters in C# 4 min read Method Overriding in C# 7 min read Anonymous Method in C# 2 min read ArraysArrays in C# 6 min read Jagged Arrays in C# 4 min read Array Class in C# 5 min read How to Sort an Array in C# | Array.Sort() Method Set - 1 8 min read How to find the rank of an array in C# 2 min read ArrayListArrayList in C# 6 min read ArrayList Class in C# 4 min read C# | Array vs ArrayList 2 min read StringStrings in C# 6 min read C# Verbatim String Literal - @ 5 min read C# String Class 9 min read C# StringBuilder 2 min read C# String vs StringBuilder 3 min read TupleC# Tuple 7 min read C# Tuple Class 3 min read C# ValueTuple 7 min read C# ValueTuple Struct 4 min read IndexersC# Indexers 5 min read C# Multidimensional Indexers 5 min read C# - Overloading of Indexers 3 min read Like