ArgumentNullException Class

Represents the error that occurs when an argument passed to a method is invalid because it is null .

Syntax

[System.Runtime.InteropServices.ComVisible(true)]
public class ArgumentNullException : ArgumentException

Remarks

Note:

ArgumentNullException is thrown when a method is invoked and at least one of the passed arguments is null and should never be null .

ArgumentNullException behaves identically to ArgumentException. It is provided so that application code can differentiate between exceptions caused by null arguments and exceptions caused by non-null arguments. For errors caused by non-null arguments, see ArgumentOutOfRangeException .

Thread Safety

All public static members of this type are safe for multithreaded operations. No instance members are guaranteed to be thread safe.

Example

The following example demonstrates an error that causes the string class to throw a ArgumentNullException exception.

C# Example

using System;
class ArgumentNullTest {
 public static void Main() {
 String[] s = null;
 String sep = " ";
 try {
 String j = String.Join(sep,s);
 }
 catch (ArgumentNullException e) {
 Console.WriteLine("Error: {0}",e);
 }
 }
}

The output is

Error: System.ArgumentNullException: Value cannot be null. Parameter name: value at System.String.Join(String separator, String[] value) at ArgumentNullTest.Main()

Requirements

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0