Compiler error in case of advanced for-each loop of Map.Entry

[Artem Danilov]

Hello!
Could anybody explain why the following code is not compile?
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Map map = new HashMap();
for (Map.Entry e: map.entrySet()){};
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"compiler error: incompatible types
found : java.lang.Object
required: java.util.Map.Entry"
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But on the other hand:
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Map map = new HashMap();
for (Map.Entry e: (Set<Map.Entry> map.entrySet()){};
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and
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Map map = new HashMap();
Itarable<Map.Entry> i = map.entrySet();
for (Map.Entry e: i){};
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...are compiled well...

[Barry Gaunt]

When using raw types, the only thing map.entrySet() can return is a Set of Objects. But you cannot assign an Object to a Map.Entry without a cast. What you can do, however, is:

Map map = new HashMap();
for (Object e: map.entrySet()){
Map.Entry me = (Map.Entry)e;
};