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    <p><strong>Short answer:</strong> </p> <p>change</p> <pre><code>this.visited = onetimevisit; </code></pre> <p>to</p> <pre><code>this.visited = new ArrayList (onetimevisit); </code></pre> <p><strong>Longer answer:</strong></p> <p><code>ArrayLists</code> are not necessarily <code>static</code>. I think you're incorrectly inferring that the <code>ArrayList</code> must somehow have been set to static from the fact that there is only one copy of the <code>ArrayList</code> when you pass it in the way you've passed it. The thing to understand is that when you pass an object in Java (an <code>ArrayList</code>, for example), you're passing a <em>reference</em> to the object. A reference is something akin to a C-style pointer with the distinction that pointer arithmetic and such is not allowed. When you call a method and pass an object, the called method just gets a copy of the reference and not a copy of the object. Likewise, when you use the = operator to assign one object to another, you're only assigning the references to equal each other, and there is still only one copy of the object. In your code, both <code>this.visited</code> and <code>onetimevisit</code> are references that come to point to the same object in memory.</p> <p>On the other hand, <code>ArrayList</code> has something that is somewhat akin to a copy constructor. This constructor, called in my sample code above, creates a shallow copy of the given <code>ArrayList</code>, which seems to be what you want. It is worth noting that an <code>ArrayList</code> does not copy the objects added to it (it stores references to them), so perhaps what you really need is to create copies of the objects as well. This would be done by calling their copy constructors (if they allow copying by providing such a constructor) before inserting them into the <code>ArrayList</code>.</p>
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    1. COThank you so much
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    2. CO@afni: The objects _in_ the list are still shared, even after copy! If you have a list of users, and you pass a copy (using new ArrayList(oldUsers)), and you change the name of the user, all lists will see the updated name.
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    3. CO@extraneon- yes. I've tried that, but I know the concept now and my mistake.
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