Javascript Dynamic pointer allocation

Question

I'm wondering whether I can assign the pointer of a variable as something along the lines of

"image"+i+".src"

I've tried using eval, because that's the only suggestion I've found, but I'm being thrown a undefined variable error. Here's my code, if someone wouldn't mind taking a look:

<html>
    <head>
        <script type="text/javascript">
        <!--
            m = 0
            x = 0
            image=[  //Initializes the Array for Image URLs, Add object by adding the full URL in "" with , in between each entry
                "http://i.imgur.com/OaElB10.jpg",
                "http://i.imgur.com/NTYiEB9.jpg",
                "http://i.imgur.com/X1jreGc.jpg"]
            function ImgPreloadHandler()
            {                
                l = image.length
                for(t=0; t<l; t++)
                {
                    var image+t = new image()
                        image+t = image[t]
                }
            }
            ImgPreloadHandler()
        //-->
        </script>
    </head>
    <body>
    <img src="http://i.imgur.com/mv3sV8m.png" name="slide" width="796" height="600" />
        <script>
            function slideit()
            {            
                var step = 0
                var z = step
                if (!document.images)//if browser does not support the image object, exit.
                    return
                        document.images.slide.src=
                    if (step<x)
                        step++
                    else
                        step=1
                setTimeout("slideit()",2500)//call function "slideit()" every 2.5 seconds
            }
        slideit()
        </script>
    </body>
</html>

There are no pointers in JavaScript, and you cannot allocate memory manually. Also you cannot (should not) create dynamic variable names. Just use the image array that you already have! — Bergi
– Bergi, Commented Dec 11, 2013 at 18:51
For your actual problem, see JavaScript Preloading Images - to preload an image, create an image html element (does not need to be in the document) and assign to the src attribute of it. — Bergi
– Bergi, Commented Dec 11, 2013 at 18:52
Don't use  unless you really, really must support Netscape 2.0 — slebetman
– slebetman, Commented Dec 11, 2013 at 19:40

Jivings · Accepted Answer · 2013-12-11 18:52:01Z

0

You can't create a dynamic variable name. But there's plenty of other solutions.

Why not create an Object that contains your image values?

var images = {};

for(t=0; t<l; t++) {
  images[image + t] = image[t];
}


console.log(images);
> { 
    image0: "http://i.imgur.com/OaElB10.jpg",
    image1: "http://i.imgur.com/NTYiEB9.jpg",
    image2: "http://i.imgur.com/X1jreGc.jpg"
  }

By the way, don't use eval :)

answered Dec 11, 2013 at 18:52

Jivings

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