Cannot resolve symbol 'facts'

It seems to me, that everything is equal like in the video, but it doesn't recognize automatically facts, and nether the length. Can anyone please help me? Thank you :) String fact = ""; //Randomly select a fact Random randomGenerator = new Random (); // Construct a new Random number generator int randomNumber = randomGenerator.nextInt(facts.length); /*Convert the randomNumber to a text fact *0 = Ants stretch when they wake up in the morning. * 1 = Ostriches can run faster then horses. * 2 = Olympic gold medals are actualy made mostly of silver.

            */
            //if randomNumber equals 0 then
          fact = facts[randomNumber];

            //Update the label with our dynamic fact
            factLabel.setText(fact);
        }
    };
    showFactButton.setOnClickListener(Listener);