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copied!<p>The error you get in your first one is:</p> <pre><code>Type mismatch: cannot convert from element type Object to Map.Entry </code></pre> <p>This is because the compiler converts your FOR-IN loop:</p> <pre><code>for (Entry entry : anyMap.entrySet()) { } </code></pre> <p>To:</p> <pre><code>for (Iterator i = anyMap.entrySet().iterator(); i.hasNext();) { Entry e = i.next(); // not allowed } </code></pre> <p>Your second example works, <strong>but only through cheating!</strong> You are doing an unchecked cast to get <code>Set</code> <em>back</em> into a <code>Set<Entry></code>.</p> <pre><code>Set<Entry> entries = anyMap.entrySet(); // you get a compiler warning here for (Entry entry : entries) { } </code></pre> <p>Becomes:</p> <pre><code>Set<Entry> entries = anyMap.entrySet(); for (Iterator<Entry> i = entries.iterator(); i.hasNext(); ) { Entry e = (Entry) i.next(); // allowed } </code></pre> <hr/> <p><strong>Update</strong></p> <p>As mentioned in comments, the type information is getting lost in both examples: because of the compiler's raw type erasure rules.</p> <p>To provide backwards compatibility, <strong>ALL</strong> methods of raw type instances are replaced by their <em>erased</em> counterparts. So, because your <code>Map</code> is a raw type, it all gets erased. Including its <code>Set<Map.Entry<K, V>> entrySet();</code> method: your raw type instance will be forced to use the erased version: <code>Set entrySet()</code>.</p>

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