how set button text randomly without duplicates?

Question

i want to set buttons text by str array in random :

String str[] = { "1", "2", "3", "4", "5", "6" };
Button buttons[] = new Button[4];

        buttons[0] = (Button) findViewById(R.id.id1);
        buttons[1] = (Button) findViewById(R.id.id2);
        buttons[2] = (Button) findViewById(R.id.id3);
        buttons[3] = (Button) findViewById(R.id.id4);

for (int i = 0; i < 4; i++) {
        Random r = new Random();
        int x = r.nextInt(str.length); 
        buttons[i].setText(str[x]);
                    }

so how can i set buttons text without duplicates? something like this:

for example, build an ArrayList and add the used Strings into it. Then check against..... — Opiatefuchs, Feb 04 '16 at 13:41
Try moving the Random r = new Random(); to before the for loop. — BryanT, Feb 04 '16 at 13:52
http://stackoverflow.com/questions/4040001/creating-random-numbers-with-no-duplicates — Fabio Venturi Pastor, Feb 04 '16 at 13:59
This question lacks any detail that would enable a confident answer. — , Feb 04 '16 at 14:06

rossum · Answer 1 · 2016-02-04T21:50:35.597

1

Your question is not very clear. I think this might be what you want:

1) Put the alternate button texts into an array, list or convenient structure.

2) Shuffle the array (or whatever) so the texts are in a random order with no repeats.

3) Pick off the texts in their shuffled order to assign to the buttons.

edited Feb 04 '16 at 21:50

answered Feb 04 '16 at 15:06

rossum

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I think, this would be the cleaner solution, for this limited set of text. – AlbAtNf Feb 05 '16 at 08:19

score 0 · Accepted Answer · answered Feb 04 '16 at 15:29

        List<Integer> setNames = new ArrayList<>();
        for (int i = 0; i < 4; i++) {
            int x;
            do {
                Random r = new Random();
                x = r.nextInt(str.length);
            }while(setNames.contains(x));
            setNames.add(x);
            buttons[i].setText(str[x]);
        }

This is another possibility. Sufficient for the four iterations.

how set button text randomly without duplicates?

2 Answers2