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Iterator in HashMap

 
Greenhorn
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What is the equivalent of iterator in HashMap? How do I loop through the objects in the HashMap?
Mansi
 
Wanderer
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You have three views which are Collections you can iterate through: keySet(), values(), and entrySet(). Many people do somethign like this:

However, this is a big waste of time, performaing a get() on every singe key, which includes a hashCode() calculation. Completely unnecessary. If you want to get both keys and values, do something like:

If you really only need the keys, use keySet(); if you only need values, use values(); if you need both, use entrySet().
 
Mansi Vyas
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Thanks.
 
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