NullPointerException in Java | Code2night.com
Code2night
  • Home
  • Blogs
  • Guest Posts
  • Tutorial
  • Post Blog
  • Register
  • Login
  1. Home
  2. Blogpost

NullPointerException in Java

Date- Aug 27,2023

1597

NullPointerException in Java

In Java, a NullPointerException is a runtime exception that occurs when you attempt to perform an operation on an object reference that is null. In other words, you're trying to access a member (like a method or field) of an object that hasn't been initialized, resulting in a null reference. Here's an example that demonstrates a NullPointerException:


package Tutorial_00;

public class Blog02 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//code that may raise exception  

		 String value = null;

	        try {
	            int length = value.length(); // This line will throw NullPointerException
	            System.out.println("Length: " + length);
	        } catch (NullPointerException e) {
	            System.out.println("NullPointerException caught: " + e.getMessage());
	        }
			  
	}

}



In this example, the variable text is declared and initialized to null. When the length() method is called on the text reference, a NullPointerException is thrown because text is null, and you can't call methods on a null reference. To avoid NullPointerException, you need to ensure that the object reference is not null before attempting to access its members. This can be done using conditional statements or by properly initializing the object before using it. For example:


package Tutorial_00;

public class Blog02 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
	    String value = "Hello, world!";

        if (value != null) {
            int length = value.length(); // This is safe
            System.out.println("Length: " + length);
        } else {
            System.out.println("value is null.");
        }
			  
	}

}


In this second example, the code checks whether the text reference is null before calling the length() method. This prevents a NullPointerException from occurring.

Comments

Tags

LinkedinLogin
LinkedinProfile
GetLinkedinProfile
C#
Aspnet
MVC
Linkedin
ITextSharp
Export to Pdf
AspNet Core
AspNet
View to Pdf in Aspnet
Model Validation In ASPNET Core MVC 60
Model Validation
Model Validation In ASPNET Core MVC
Model Validation In ASPNET
Image Compression in AspNet
Compress Image in c#
AspNet MVC
Free Download for Youtube Subscribers!

First click on Subscribe Now and then subscribe the channel and come back here.
Then Click on "Verify and Download" button for download link

Subscribe Now | 1210
Download
Support Us....!

Please Subscribe to support us

Thank you for Downloading....!

Please Subscribe to support us

Continue with Downloading
Be a Member
Join Us On Whatsapp Join Us On Facebook

Welcome To Code2night, A common place for sharing your programming knowledge,Blogs and Videos

  • Panipat
  • info@Code2night.com

Links

  • Home
  • Blogs
  • Tutorial
  • Post Blog

Popular Tags

Copyright © 2025 by Code2night. All Rights Reserved

  • Home
  • Blog
  • Login
  • SignUp
  • Contact
  • Terms & Conditions
  • Refund Policy
  • About Us
  • Privacy Policy
  • Json Beautifier
  • Guest Posts