Math.random() and variable

Question

how can i randomize for this variable one word?

var = 'stack';

for (i=0; i<5; i++){
   document.write( Math.random() ??? + '<br />');
}

sample result:

t
c
k
a
s

thanks

http://stackoverflow.com/questions/3943772/how-do-i-shuffle-the-characters-in-a-string-in-javascript ? — stecb, May 16 '11 at 16:09

score 1 · Answer 1 · answered May 16 '11 at 16:10

1

Here is a solution:

var st = 'stack';

for (i=0; i<st.length; i++){
    var random = (Math.random() * st.length);
    document.write( st.slice(random, random+1) + '<br />');
}

Fiddle: http://jsfiddle.net/maniator/Xx4NA/ (keep pressing Run to see it run differently every time)

answered May 16 '11 at 16:10

Naftali

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@Neal -- when I ran your fiddle I got the following: c k s a c – El Guapo May 16 '11 at 16:13
@ElGuapo, it is random, every `run` will have a different result – Naftali May 16 '11 at 16:13
Right on.. yeah.. guess that makes sense... I thought @tox wanted each letter to show up, but randomized. Probably a bad assumption. – El Guapo May 16 '11 at 16:14
Is it suppose to be using individual chars more than once? Or is it suppose to merely shuffle the order of the chars? – Sampson May 16 '11 at 16:15
@Jonathan, i am not the OP, i just went with what it looked like the answer was to the query – Naftali May 16 '11 at 16:16
@Neal I was only asking since the OP's example appear to be a shuffling of the letters alone. – Sampson May 16 '11 at 16:21
@Jonathan, i understand your question. i think we are all a bit thrown by the OP's example, but the OP said that that was a `sample result` which can mean there could be more results – Naftali May 16 '11 at 16:22
@tox, pick one tho lol, stop goin back and forth, its making me dizzy – Naftali May 16 '11 at 16:51

Thomas Li · Accepted Answer · 2011-05-16T16:39:33.890

1

Revised as Neal pointed out that the previous solution does not take into account of duplicated letters:

var randomIndexes = new Array();
for (i = 0; i < word.length; i++) {
    randomIndexes[i] = -1;
}

for (i = 0; i < word.length; i++) {
    while (randomIndexes[i] == -1) {
        randomIndexes[i] = Math.floor(Math.random() * word.length);
        for (j = 0; j < i; j++) {
            if (randomIndexes[i] == randomIndexes[j]) {
                randomIndexes[i] = -1;
                break;
            }
        }
    }
}

for (i = 0; i < word.length; i++) {
    document.write(word.charAt(randomIndexes[i]));
}

edited May 16 '11 at 16:39

answered May 16 '11 at 16:14

Thomas Li

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What if OP wants each letter to appear once? – Thomas Li May 16 '11 at 16:18
@Thomas, the OP did not specify, and that code still seems to long even in that aspect – Naftali May 16 '11 at 16:18
@Thomas, also your under the assumption that OP does not want to use a word like `glass` that has 2 `s`'s – Naftali May 16 '11 at 16:19
@Neal Revised solution. Not the greatest solution but it will do. – Thomas Li May 16 '11 at 16:27
@tox Probably just simple bugs. Go through the code and make sure you understand the concept. – Thomas Li May 16 '11 at 16:33
@tox Try this revised solution again. – Thomas Li May 16 '11 at 16:39

Math.random() and variable

2 Answers2