Shuffling a char() array.

jcov

Hey, just wondering if anyone could give me a hand with shuffling.

I've got an char array and I would like to shuffle and print the updated array when the mouse is pressed.

Thanks :)

char [] letters;

void setup() {
  size (500, 500);
  creating_letters();
}

void draw () {

  background(200);

  //input size here
  printing_letters(30);
}

void creating_letters () {
  letters = new char [20];

  for (int i = 0; i < letters.length; i++) {
    letters [i] = (char) int(random(33, 100));
  }
}

void printing_letters(int size) {

  int textSize = size;
  for (int i = 0; i<letters.length; i++) {
    textSize(textSize);
    fill(0);
    text((letters[i]), ((i*(textSize/1.3))+10), height/2);
    fill(255);
  }

 if ((mousePressed) && (mouseButton == LEFT)){
   Shuffle();
 }
}


void Shuffle () {

//not sure what to do :/
  letters = sort (letters, int(random(letters.length)));

}

GoToLoop

https://forum.Processing.org/two/discussion/20529/retrieving-elements-from-a-list-randomly#Item_5

jcov

Sorry i'm kinda new to programming >__<

so, can I add ".toCharArray()" onto the end of the statement line 20? It's giving me errors on my end.

Is ".toCharArray()" Java code?

GoToLoop

Method toCharArray() belongs to class String:
http://docs.Oracle.com/javase/8/docs/api/java/lang/String.html#toCharArray--

But if you've already got a char[] array, you can directly invoke the customized shuffle() function.

jcov

Cool, I got it working :) .

If you can, would you be able to suggest a resource to help better understand the code that you referenced? I don't really know how it's sorting the array haha.

GoToLoop

I haven't invented this algorithm. Merely adapted it to Java Mode & p5.js. :ar!
It's called Fisher-Yates Shuffle. Visit this link for it: http://Bost.Ocks.org/mike/shuffle/ :-bd