In Java I am told that when doing a null check one should use == instead of .equals(). What are the reasons for this?

May 1, 2010 · Understanding the difference between “IS NULL” and “= NULL” When a variable is created in SQL with the declare statement it is created with no data and stored in the variable …

So if you don't need to support the difference between empty and null/absent string you may also consider the empty parameter as null. If instead you want to recreate point 4. of JSON …

Jun 28, 2011 · To expound slightly on GlennG's very helpful answer (translating the syntax from C# to VB.Net is not always "obvious") you can also decorate individual class properties to …

In other words, a null pointer is a pointer of any type pointing at a well-defined "nowhere". Any pointer can turn into a null pointer when it is assigned a null pointer constant. The standard …

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from …

The null value (which is different than an empty string "", a valid String instance) can never have a method invoked upon it. Placing the "known non-null" (usually a constant value or literal) to the …

96 Checking null with normal equality will also return true for undefined. if (window.variable == null) alert('variable is null or undefined');

I have some code and when it executes, it throws a NullReferenceException, saying: Object reference not set to an instance of an object. What does this mean, and what can I do to fix …

This Stack Overflow question discusses the correct way to represent null XML elements.