I know how do this in PHP, but in javascript arrays are weird.
So I have a set of image transitions which have effects that use easing equations. For certain effects I want to pick up a random value from a array of multiple values:
something like:
easing: randomFrom(array('easeOutElastic', 'easeOutBounce', 'easeOutSince')),
function randomFrom(array) {
return array[Math.floor(Math.random() * array.length)];
}
// in your code
easing: randomFrom(['easeOutElastic', 'easeOutBounce', 'easeOutSince']),
Try this:
function randomFrom(arr){
var randomIndex = Math.floor(Math.random() * arr.length);
return arr[randomIndex];
}
For a demo I was trying to get a random easing string ;)
function getRandomEasing() {
var easingArr = [];
for(easing in $.easing){
easingArr.push(easing);
}
var rnd = Math.floor(Math.random() * easingArr.length);
return easingArr[rnd];
}
var randomEasing = getRandomEasing();
Fun demo: http://jsfiddle.net/aamir/psWvy/
$.easing? jsfiddle.net/psWvy/2I am a late comer to this question. If you don't mind adding a method to Array, you can:
Array.prototype.pickARandomElement = function() {
return this[Math.floor(Math.random() * this.length)];
}
test run:
> [10, 123, 777].pickARandomElement()
10
> [10, 123, 777].pickARandomElement()
777
> [10, 123, 777].pickARandomElement()
777
> [10, 123, 777].pickARandomElement()
123
The following is just for fun:
Array.prototype.pickARandomElement = function() {
return this.sort(function() { return Math.random() - 0.5; })[0];
}
it is like shuffling a deck of cards and returning the top card. But its time complexity is O(n log n) so I wouldn't really use it, and it is just for fun. The first solution here is a solution with O(1).
