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    <p>Your "another approach" is correct, this is how it's usually done.</p> <p>And as for the problem of <code>i</code> always being a constant, that's how closures work! You see, when you create this function that does something with <code>i</code> (like <code>function() { alert(i); }</code>), that function, as they say, <em>'captures'</em>, or <em>'binds'</em> the variable <code>i</code>, so that variable <code>i</code> does not die after the loop is finished, but continues to live on and is still referenced from that function.</p> <p>To demonstrate this concept, consider the following code:</p> <pre><code>var i = 5; var fn = function() { alert(i); }; fn(); // displays "5" i = 6; fn(); // displays "6" </code></pre> <p>When it is written in this way, the concept becomes a bit more evident, doesn't it? Since you're changing the variable in the loop, after the loop is finished the variable retains it's last value of <code>(1+steps)</code> - and that's exactly what your function sees when it starts executing.</p> <p>To work around this, you have to create another function that will return a function. Yes, I know, kind of mind-blowing, but bear with me. Consider the revised version of my example:</p> <pre><code>function createFn( theArgument ) { return function() { alert( theArgument ); }; } var i = 5; var fn = createFn( i ); fn(); // displays "5" i = 6; fn(); // still displays "5". Voila! </code></pre> <p>This works, because the <code>fn</code> function no longer <em>binds</em> the variable <code>i</code>. Instead, now it binds another variable - <code>theArgument</code>, which has nothing to do with <code>i</code>, other than they have the same value at the moment of calling <code>createFn</code>. Now you can change your <code>i</code> all you want - <code>theArgument</code> will be invincible.</p> <p>Applying this to your code, here's how you should modify it:</p> <pre><code>function createTimeoutHandler( elemArg, iDivStepsArg ) { return function() { setOpacity( elemArg, iDivStepsArg ); }; } for (var i = 1; i &lt;= steps; i++) { console.log(i/steps + ', ' + (i/steps) * duration); setTimeout( createTimeoutHandler( elem, i/steps ), (i/steps) * duration); } </code></pre>
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    1. POJavascript: how to pass different object to setTimeout handlers created in a loop?
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    1. USFyodor Soikin
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      1. VTUpMod
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    1. COThanks for the suggestion! Is this, as thomasrutter says, less efficient than doing it the way he says?
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    2. COAs for creating multiple setTimeouts, I completely agree: it would be more efficient to reinitialize after each iteration.
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    3. COAh ok, thanks then. +1 because your solution worked, but I'll accept thomasrutter's solution as i'll use that :)
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