Android Quote app, next and back buttons
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Im trying to make a simple quote app, but every time I hit my back button after my next button it will go to the next array and not backwards. Im using an int num to keep track of with quote the user is on. 
here is my back button

    public void back(View B){
	 quotes[0]= "Love is timeless";
       quotes[1]= "I hate you";
       quotes[2]= "arggg!";
       quotes[3]= "The end is near";
       quotes[4]= "Leave be";  

     TextView text = (TextView) findViewById(R.id.Quote);
     text.setText(quotes[num--]);



and here is my next button

    public void next(View N){
    quotes[0]= "Love is timeless";
		        quotes[1]= "I hate you";
		        quotes[2]= "arggg!";
		        quotes[3]= "The end is near";
		        quotes[4]= "Leave be";

		        if(num == 5){
		            num =0;}

		       TextView text = (TextView) findViewById(R.id.Quote);
		       text.setText(quotes[num++]);
		       


please help! ive been searching for hours
		       