????entrySet????key+value??д??1????

Iterator<Entry<String?? String>> iter = map.entrySet().iterator();
Entry<String?? String> entry;
while (iter.hasNext()) {
    entry = iter.next();
    key = entry.getKey();
    value = entry.getValue();
}

????entrySet????key+value??д??2????

for (Entry<String?? String> entry: map.entrySet()) {
    key = entry.getKey();
    value = entry.getValue();
}

????2.2.2 ????key

????keySet????key??д??1????

Iterator<String> iter = map.keySet().iterator();
while (iter.hasNext()) {
    key = iter.next();
}

????keySet????key??д??2????

for (String key : map.keySet()) {
}

????entrySet????key??д??1????

Iterator<Entry<String?? String>> iter = map.entrySet().iterator(); 
while (iter.hasNext()) {
    key = iter.next().getKey();
}

????entrySet????key??д??2????

for (Entry<String?? String> entry: map.entrySet()) {
    key = entry.getKey();
}

????2.2.3 ????value

????keySet????value??д??1????

Iterator<String> iter = map.keySet().iterator();
while (iter.hasNext()) {
    value = map.get(iter.next());
}

????keySet????value??д??2????

for (String key : map.keySet()) {
    value = map.get(key);
}

????entrySet????value??д??1????

Iterator<Entry<String?? String>> iter = map.entrySet().iterator();
while (iter.hasNext()) {
value = iter.next().getValue();
}

????entrySet????value??д??2????

for (Entry<String?? String> entry: map.entrySet()) {
    value = entry.getValue();
}

????values????value??д??1????

Iterator<String> iter = map.values().iterator();
while (iter.hasNext()) {
value = iter.next();
}

????values????value??д??2????

for (String value : map.values()) {
}