Boolean Object and boolean variable issue in JAVA

Question

I declare a Boolean variable. For example Boolean dataVal=null;
Now if I execute the following code segment:

if(dataVal)
    System.out.prin         


        

Answer 1

You can have a look at the specification for unboxing issues, your situation is described here section 5.1.8 Unboxing Conversion : If r is null, unboxing conversion throws a NullPointerException

That means your if ( /* Boolean object */ ) will never be unboxed into a boolean primitive type and therefore throw a NPE because you are doing an invalid if(null).

By the way, unboxing will work if you had:

final Boolean booleanTest = new Boolean (true);
if (booleanTest) {
    // Do something
}