Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

check if a field can be set to null

Posted on 2004-10-15
6
221 Views
Last Modified: 2010-03-31

How do you check if a field can be set to null?  Can you write code that throws an exception......

0
Comment
Question by:bcsmess
6 Comments
 
LVL 14

Assisted Solution

by:Tommy Braas
Tommy Braas earned 175 total points
ID: 12320549
Hi bcsmess,

All non-native field types in Java can be set to null. If you have accessors to all variables you can enforce that only non-null values are set.

Cheers!

\tt
0
 
LVL 11

Accepted Solution

by:
cjjclifford earned 175 total points
ID: 12320647
orangehead911, how about:

class MyClass {
    private static final String myString = "hello";

    private void setNull() {
        // This is not allowed....
        myString = null;
    }
}

Of course, my example is a compile error... but yes, all non-final attributes can be set to null...
0
 

Author Comment

by:bcsmess
ID: 12320884
how about final attributes?
0
Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

 
LVL 9

Expert Comment

by:Venci75
ID: 12321059
You will get a compilation error if you try to set a value to a final field.
0
 
LVL 11

Expert Comment

by:cjjclifford
ID: 12321259
as I pointed out...
0
 
LVL 14

Expert Comment

by:Tommy Braas
ID: 12321638
> orangehead911, how about:

Stating the obvious, final fields aren't variables...they are constants.
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Arrays.asList  VS  ArrayList 4 71
table example 4 32
How to execute a Python program and gather return output in Java 2 40
Java class and jar 3 20
After being asked a question last year, I went into one of my moods where I did some research and code just for the fun and learning of it all.  Subsequently, from this journey, I put together this article on "Range Searching Using Visual Basic.NET …
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question