How can I select the first 5 random elements
<ul>
<li>First</li>
<li>Second</li>
<li>Third</li>
...
<li>N</li>
</ul>
alert($("li:random").text());
but it takes all random elements. I only want the first 5.
Is there another way to do the same thing?
Using the Fisher-Yates shuffle I have created a small script for this purpose. This is done by first creating a randomly shuffled and sliced copy of the array of jQuery elements, and then filtering out all elements that do not exist in both arrays.
You can read about it at http://www.afekenholm.se/jquery-rand. Here's the script:
/**
* jQuery.rand v1.0
*
* Randomly filters any number of elements from a jQuery set.
*
* MIT License: @link http://www.afekenholm.se/license.txt
*
* @author: Alexander Wallin (http://www.afekenholm.se)
* @version: 1.0
* @url: http://www.afekenholm.se/jquery-rand
*/
(function($){
$.fn.rand = function(k){
var b = this,
n = b.size(),
k = k ? parseInt(k) : 1;
// Special cases
if (k > n) return b.pushStack(b);
else if (k == 1) return b.filter(":eq(" + Math.floor(Math.random()*n) + ")");
// Create a randomized copy of the set of elements,
// using Fisher-Yates sorting
r = b.get();
for (var i = 0; i < n - 1; i++) {
var swap = Math.floor(Math.random() * (n - i)) + i;
r[swap] = r.splice(i, 1, r[swap])[0];
}
r = r.slice(0, k);
// Finally, filter jQuery stack
return b.filter(function(i){
return $.inArray(b.get(i), r) > -1;
});
};
})(jQuery);