pic16f84 i/o port doubt

[mihir08]

im making a line folllower with pic16f84a
i am using port b as i/p lines from sensors . i am using portb.0 to portb.4 .
i wanted to know if the remaining lines are open , are they considerd to be at logic 0 .

 

[btbass]

You can turn on the internal pull up resistors, then they will read as logic 1.
It's not good to have unconnected inputs, their state is unknown and they can oscillate.
Another solution is to configure them as outputs and set them to 0.