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create dynamic vars

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May 07.2008

Ok a simple problem (I hope)… I have a few images that preload. When i call the script fo the image to load i want to be able to determine the height of the image being loaded. The problem arises when I want the image to load randomnly.

[CODE]
Image1= new Image(478,400)
Image1.src = “http://www.mysite.com/image1.jpg”

Image2 = new Image(368,400)
Image2.src = “http://www.mysite.com/image2.jpg”
var maxpics = 2;
var picheight
function picload() {

if (randnum > maxpics) {
randnum = 1;
}
var newimg = [“Image”+randnum].src; <—-//I know this is wrong, this is where I am stuck…
picheight= newimg.height;
}
[/CODE]

i want picheight to return the height of the random img source. I don’t know how to combine the variables so it will work or not come out undefined. Thanks in advance for any help.

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JavaScript

5 Comments(s) ↴

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@GSharpMay 07.2008 — You want to use eval to turn the string into an actual variable. So it should look something like:

var newimg = eval("Image"+randnum);
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@javaddikauthorMay 07.2008 — Thanks for the quick reply. Works great, I knew it was something simple I was forgetting.
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@Declan1991May 07.2008 — Or window["Image"+randnum].src;

I prefer that method.
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@toicontienMay 07.2008 — You should be using an array here.
var imgs = [];
function loadImage(src, width, height) {
var i = imgs.push( document.createElement("img") ) - 1;
imgs[i].src = src;
imgs[i].width = width;
imgs[i].height = height;
return i;
}

loadImage("http://www.mysite.com/image1.jpg", 478, 400);
loadImage("http://www.mysite.com/image2.jpg", 368, 400);
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@javaddikauthorMay 07.2008 — Now that you mention it an array probably would work better in my situation being I have up to 10 images. I will revise using the sample. Thanks for all the help.

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