nullable bool in if() statement - checks required?

Question

I just came across this in a coworkers code. He has a nullable bool type that he compares like this:

//foo has no value here and evaluated to false
if(foo==true)
{
    doSomething();
}

Typically, the way I check a nullable boolean is something like this:

bool IsTrue(bool? value)
{
   return value.HasValue && value.Value;
}

if(IsTrue(foo)){
   doSomething()
}

Edit: I ran through both methods and they both appear work the same way. I'm asking which one is the correct way and if the extra checks are necessary??

Now I am questioning both myself and my coworkers code. Is there any point in me doing this extra check here? Or can I safely do it the first way?

Thanks (and yes I did search for this! :))

Answer 1

Actually I don't recommend you to treat null as false. Either use non-nullable boolean, or explicitly handle null value. One more option to do that:

if (foo ?? false)
{

}

Answer 2

I'd use this.

bool IsTrue(bool? value)
{
   return value.GetValueOrDefault();
}

This will return false when null or false and true only when it has a value and true.

Note: You cannot use bool? in if statement, as if statement requires anything which is implicitly convertible to Boolean. where as bool? is not convertible to boolean, so compiler will complain.