Pick a random element from a string array?

Question

I've got this code, which (I hope) reads from a text file with 66 words and puts the words into an array.

BufferedReader buff = null;
String wordlist=new String[66];
int i=0;

try {
    buff = new BufferedReader(new FileReader("C:\\easy.txt"));
    wordlist[i] = buff.readLine();
    while(wordlist[i] != null&i<66){
        wordlist[i]=buff.readLine();
        i++;
    }
}

I want to pick a random word from the array. However trying a few things myself and looking at other questions doesn't seem to work. Any help would be appreciated

Could you show us what you've tried and in what way it 'doesn't seem to work'? — PakkuDon, Aug 05 '14 at 23:59
http://stackoverflow.com/questions/7961788/math-random-explained — Jorge Campos, Aug 06 '14 at 00:00

score 18 · Answer 1 · answered Aug 06 '14 at 00:03

18

The simplest code IMHO would be:

String word = wordlist[new Random().nextInt(wordlist.length)];

answered Aug 06 '14 at 00:03

Bohemian

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score 3 · Answer 2 · answered Aug 06 '14 at 00:00

3

This should work:

String randomString = wordlist[(int)(Math.random() * wordlist.length)];

answered Aug 06 '14 at 00:00

David Koelle

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1

I've learned since posting this answer about the difference between Math.random() vs. Random.nextInt(). http://stackoverflow.com/questions/738629/math-random-versus-random-nextintint – David Koelle Aug 06 '14 at 00:04
I'm not sure if this works. I've set it to display the word that it picked on a label and all it says "null". I've got all the code on the same button, so that possibly has something to do with it. Any suggestions? – Logger Aug 06 '14 at 02:38
This code definitely works. You might be having an issue if you're using a variable inside the action listener of your button that you have declared outside of your button, but without seeing your code, I cannot be sure. – David Koelle Aug 06 '14 at 22:53

score 0 · Answer 3 · answered Aug 05 '14 at 23:59

0

Generate a random number between 0 and 65, and then use that number as the index of which String you choose.

answered Aug 05 '14 at 23:59

Honinbo Shusaku

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score 0 · Answer 4 · answered Aug 06 '14 at 00:02

You can create a random number generator (an instance of Random).

Then you call the method nextInt(wordList.length) to get a random index on your array of string.

For example:

Random random = new Random(); int index = random.nextInt(wordList.length);

Then: wordList[index] to get the randomly selected string.

score 0 · Answer 5 · answered Aug 06 '14 at 00:07

0

One solution is to is to select a random number from the wordlist array by doing
String = randomWord = wordlist[(int)Math.random() * wordlist.length]
or
String randomWord = wordlist[(int)Math.random() * 66]

answered Aug 06 '14 at 00:07

Zavax

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Pick a random element from a string array?

5 Answers5

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