javascript: random image selected on refresh

Question

So I have a site in which I have a description area and I have it be a random description on refresh by using the following code:

<script type="text/javascript">
var description = new Array ();
description[0] = "I can change";
description[1] = "Isn't it cool";
description[2] = "these are just to show you guys";
description[3] = "another thing";
var size = description.length
var x = Math.floor(size*Math.random())
document.write(description[x]);
</script>

Now my question, is if I wanted to have it display random images on refresh rather than a random description, how would I do it? I assume it will take a bit of jquery and maybe some appending, but I'm really not sure.

Thanks!

Solution 1

How about:

HTML:

<img id="image" />

JS:

var description = [
  "http://static.ddmcdn.com/gif/lightning-gallery-17.jpg",
  "http://static.ddmcdn.com/gif/lightning-gallery-18.jpg",
  "http://static.ddmcdn.com/gif/lightning-gallery-19.jpg",
  "http://static.ddmcdn.com/gif/lightning-gallery-20.jpg",
  "http://static.ddmcdn.com/gif/lightning-gallery-21.jpg"
];

var size = description.length
var x = Math.floor(size*Math.random())
document.getElementById('image').src=description[x];

No jQuery necessary.

Solution 2

http://jsfiddle.net/mohammadAdil/SvswX/

<img id='random'/>

script -

var image = new Array ();
image[0] = "http://placehold.it/20";
image[1] = "http://placehold.it/30";
image[2] = "http://placehold.it/40";
image[3] = "http://placehold.it/50";
var size = image.length
var x = Math.floor(size*Math.random())

$('#random').attr('src',image[x]);

Comments

[nnnnnn]

+1. Note that this would need to be in a script element that appears after the <img>, or wrapped in an onload handler.

[Jared Michael Czerew]

@urban_racoons - would this code work if I'm using images in the asset pipeline in Rails? IE- var description = [ "images/imageOne.jpg", etc etc

[urban_raccoons]

@JaredMichaelCzerew yeah as long as <img src="images/imageOne.jpg"> would evaluate correctly. If this code is inside a rails template, there's likely a (better?) way to do this using the rails framework itself.