Use the NullReferenceException : Exception Class « Language Basics « C# / C Sharp

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C# / C Sharp » Language Basics » Exception ClassScreenshots 
Use the NullReferenceException
Use the NullReferenceException

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Use the NullReferenceException. 
 
using System;  
  
class 
  int x; 
  public X(int a) { 
    x = a; 
  
 
  public int add(X o) { 
    return x + o.x; 
  

   
// Demonstrate NullReferenceException. 
public class NREDemo {   
  public static void Main() {   
    X p = new X(10)
    X q = null// q is explicitly assigned null 
    int val; 
 
    try 
      val = p.add(q)// this will lead to an exception 
    catch (NullReferenceException) { 
      Console.WriteLine("NullReferenceException!")
      Console.WriteLine("fixing...\n")
 
      // now, fix it 
      q = new X(9);   
      val = p.add(q)
    
 
    Console.WriteLine("val is {0}", val)
  
  }  
}


           
       
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