android: randomize JSON array number

Question

setImage(cachedImage1, image1, prjcts.get(x)); setImage(cachedImage2, image2, prjcts.get(x); setImage(cachedImage3, image3, prjcts.get(x));

I need to replace x from prjcts.get(x) with a random number between 1 until the maximum entry on my JSON file. The maximum number should be felxible, I can add and delete the entry as much as I want. And one more thing, the numbers aren't allowed to be the same between each other.

Can anybody help me with this?

Thank you very much.

Haphazard · Accepted Answer · 2011-04-27 16:56:16Z

1

Try creating a List list and fill it with values from 1 to jsonMax. Then use Java Collections.shuffle(..) to randomize the list.

List<Integer> list = new ArrayList<Integer>();
int jsonMax = getMaxFromJSON(); //supplied by you
for(int i = 1; i<=jsonMax; i++)
    list.add(i);

Collections.shuffle(list);

Increment through list to get the random numbers.

edited Apr 27, 2011 at 16:56

answered Apr 27, 2011 at 15:47

Haphazard

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3 Comments

hectichavana Over a year ago

So I did this, but then the program crashed: int i=0; List<Integer> list = new ArrayList<Integer>(); Random generator = new Random(); int jsonMax = prjcts.size(); //supplied by you for(i = 1; i<=jsonMax; i++) list.add(i); Collections.shuffle(list); setImage(cachedImage1, image1, prjcts.get(i));

Haphazard Over a year ago

I can't help without seeing the stack trace.

Haphazard Over a year ago

Find the exception in the logcat. You can type adb logcat into your command prompt if you have adb setup properly in your environment variables (in Windows). It should also be available in your DDMS perspective in Eclipse.

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