Check if null Boolean is true results in exception

Question

I have the following code:

Boolean bool = null;

try 
{
    if (bool)
    {
        //DoSomething
    }                   
} 
catch (Exception e) 
{
    Syst         


        

Answer 1

Boolean is the object wrapper class for the primitive boolean. This class, as any class, can indeed be null. For performance and memory reasons it is always best to use the primitive.

The wrapper classes in the Java API serve two primary purposes:

1. To provide a mechanism to “wrap” primitive values in an object so that the primitives can be included in activities reserved for objects, like as being added to Collections, or returned from a method with an object return value.
2. To provide an assortment of utility functions for primitives. Most of these functions are related to various conversions: converting primitives to and from String objects, and converting primitives and String objects to and from different bases (or radix), such as binary, octal, and hexadecimal.

http://en.wikipedia.org/wiki/Primitive_wrapper_class