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    <p>You use three loops:</p> <pre><code>// READ THE BELOW BEFORE YOU RUN THIS var r, g, b, rarray, garray, barray; rarray = []; for (r = 0; r &lt; 256; ++r) { garray = []; rarray.push(garray); for (g = 0; g &lt; 256; ++g) { barray = []; garray.push(barray); for (b = 0; b &lt; 256; ++b) { barray.push({r: r, g: g, b: b}); } } } </code></pre> <p>That produces an array (<code>rarray</code>) of arrays (each <code>garray</code>), each of which in turn contains an array (each <code>barray</code>) of objects. Each object has an <code>r</code>, <code>g</code>, and <code>b</code> value.</p> <p>Note that <a href="https://stackoverflow.com/questions/6007377/generating-0-255-3-times-double-or-triple-loop/6007518#6007518">as selbie points out</a>, you'll end up with a total of <code>256 * 256 * 256 = 16,777,216</code> entries spread across the various arrays. You'll have <code>256 * 256 = 65,536</code> <code>barray</code>s and <code>256</code> <code>garray</code>s. In all, that's <code>1 + 256 + (256 * 256) + (256 * 256 * 256) = 16,843,009</code> objects. Since all of these objects (<a href="http://blog.niftysnippets.org/2011/01/myth-of-arrays.html" rel="nofollow noreferrer">including the arrays</a>) are actually key=value maps, each entry will have a key portion and a value portion, and so just the references to those will be four bytes each. Then there's the actual key data for the array entries (1-3 characters = 2-6 bytes <em>minimum</em>) and the key data for each of our 16M final objects (which have three keys each, <code>r</code>, <code>b</code>, and <code>g</code>). Plus some other overhead. The details will vary a <em>lot</em> by JavaScript environment, but we're probably talking <em>no less than</em> (waves hands) 32-64 bytes per entry, for a total in memory of ~538MB-1076MB. Now, that's not a lot by modern computer standards, but it's a lot for a web page. :-) I used Chrome to do it, and it took ~1GB (did it in about 4 seconds&nbsp;&mdash; gotta love Chrome). In contrast, after several minutes and >2GB of RAM use, I gave up on Firefox. I wouldn't go near this in IE with a barge-pole.</p> <p><a href="http://jsbin.com/imoyo4/2" rel="nofollow noreferrer">Live example</a> (using only <code>0..4</code> rather than <code>0..255</code>).</p>
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    1. POGenerating 0-255 3 times... double or triple loop?
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    1. POGenerating 0-255 3 times... double or triple loop?
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    1. COYeah I'm aware of the 16,000 number of color combos, i didn't want to print them all out, just save in an array. I was just doing console.log to see what i was getting, hence the smaller number range (25).
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    2. COi knew it had to be a triple loop. is there anyway to do it in less than that though? and i mean without using a helper function or other thing like that. i mean, for example i was trying stuff like: [].forEach(num.push()) or something along that lines of psuedo. It's just so much simpler to create the same thing.
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    3. CO@jaredwill: 16 *million*, not 16 thousand. Even just putting them in an array will be very, very expensive and won't work on many browsers out there. And why do it? Just looking something up in the array involves just as much calculation as actually creating the thing. No, there's no "shorter" way to do it (I don't think the loops are long, frankly). There is a way to use `forEach` to do it (on browsers that support `forEach`, it's quite new), but it doesn't buy you anything in terms of brevity (in this case) and adds the over head of function calls.
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