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

When you have a boolean it can be either true or false. Yet when you have a Boolean it can be either Boolean.TRUE, Boolean.FALSE or null as any other object.

In your particular case, your Boolean is null and the if statement triggers an implicit conversion to boolean that produces the NullPointerException. You may need instead:

if(bool != null && bool) { ... }