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    <blockquote> <p>But this will create an Iterator object behind the scenes (I think?)</p> </blockquote> <p>Yes it will.</p> <blockquote> <p>The best I have come up with is this code:</p> <pre><code> Object[] values = myMap.values.toArray(); ...standard "int i" for loop on the array </code></pre> <p>But to be honest I am not sure what the GC will do with this array.</p> </blockquote> <p>In fact this is going to be worse than using an <code>Iterator</code> explicitly or implicitly:</p> <ul> <li>The <code>toArray()</code> method allocates a new array and copies the value-set elements into it. </li> <li>The call to <code>values()</code> <em>may</em> instantiate a <code>Set</code> object.</li> <li>The call to <code>toArray()</code> internally calls <code>iterator()</code> on the value set object which creates a new <code>Iterator</code> instance.</li> </ul> <p>So you are allocating an <code>Iterator</code> anyway, AND a temporary array, AND (possibly) a <code>Set</code> object.</p> <hr> <blockquote> <p>I profiled the heap and the largest set of objects was <code>ArrayList$Itr</code> (not related to this <code>HashMap</code> example, but I am currently rewriting all enhanced for loops to standard for loops)</p> </blockquote> <p>As you point out, that is a different case. But I still think you are barking up the wrong tree here. If you are using a recent HotSpot JVM, the cost of allocating and garbage collecting short-lived objects (i.e. ones that don't get tenured) is <em>pretty small</em>. Unless you have a specific reason to reduce the object allocation rate, all of your work may achieve little in terms of actual measurable performance improvement.</p>
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    1. POIterate over values of a HashMap without creating any new objects to be Garbage Collected
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    1. POIterate over values of a HashMap without creating any new objects to be Garbage Collected
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    1. COThanks for the info, it clears some things up for me. One thing is that since this is an Android game, it is on the Dalvik VM and not HotSpot.
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    2. COI understand that Davlik VM's GC is not be as good as Hotspot's. But I still would only optimize the use of iterators if your app / game was experiencing GC pauses.
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