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Randomly select x elements from an array

Posted on 2010-11-22
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Last Modified: 2012-05-10
I have an array, like:
$array = array('dog','cat','sam','puppy','mouse','coke');

How can I create a new array, that has only x number of elements, randomly chosen from $array?
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Question by:interclubs
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5 Comments
 
LVL 20

Expert Comment

by:DVation191
ID: 34190086
http://php.net/manual/en/function.array-rand.php

$x = 3;
$array = array('dog','cat','sam','puppy','mouse','coke');
$rand_keys = array_rand($array , $x);
echo $input[$rand_keys[0]] . "\n";
echo $input[$rand_keys[1]] . "\n";
echo $input[$rand_keys[3]] . "\n";
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LVL 13

Accepted Solution

by:
dsmile earned 500 total points
ID: 34190281
Use shuffle() to make array randomly ordered, and then pick up x element(s) to create new array by using array_splice()
<?php
$array = array('dog','cat','sam','puppy','mouse','coke');

//reorder the array randomly
shuffle($array);

//create new array
$n = 3; // change this to x number you want
$newarray = array_splice($array, $n);

print_r($newarray);

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Author Closing Comment

by:interclubs
ID: 34190497
nice.
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LVL 20

Expert Comment

by:DVation191
ID: 34190561
Just curious for my own future reference...what was wrong with my solution?
0
 

Author Comment

by:interclubs
ID: 34190606
It didn't work. I think you meant:

$x = 3;
$array = array('dog','cat','sam','puppy','mouse','coke');
$rand_keys = array_rand($array , $x);
echo $array[$rand_keys[0]] . "\n";
echo $array[$rand_keys[1]] . "\n";
echo $array[$rand_keys[2]] . "\n";

(Changed parts in bold). That made it work, but it still wasn't giving me a new array, it was just randomly picking elements from an array.
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