Question

I wonder how I could navigate between the strings within an array, using the previous and next buttons, these strings will be displayed in a TextView. Thank you!

protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView (R.layout.activity_f3);
    setTitleFromActivityLabel (R.id.title_text);

    TextView cumulos = (TextView) findViewById(R.id.cumulos);
    TextView respostas = (TextView)findViewById(R.id.respostas);

    Random randPhrase = new Random();
    String[] cum = getResources().getStringArray(R.array.cumulos);
    String[] resp = getResources().getStringArray(R.array.resp_cumulos);

    String textout = "";
    String textresp = "";

    for (int i = 0; i < cum.length; i++) {
        for (int j = 0; j < resp.length; j++) {
            textresp = resp[j];
        }
        textout = cum[i];
    }

    cumulos.setText(textout);
    respostas.setText(textresp);
}

Answer 1

Declare one int for index starting with 0 then in NextButton do

if(!index > resp.length-1 )  //not greater than array length
{
setText(resp[index++]);
}
else { nextButton.setEnabled(false); nextButton.setClicable(false); } //not clickable anymore

in PreviousButton do

if(!index < 0)
{
   setText(resp[index--]);
}
else{
prevButton.setEnabled(false); 
prevButton.setClicable(false);
}

Something like this? Mind this code is not tested, might throw exceptions.
It just to give you an idea.