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This is what I tried to do, but it gives me a warning:
HashMap<String, String>[] responseArray = new HashMap[games.size()]; Type safety: The expression of type HashMap[ ] needs unchecked conversion to conform to HashMap[ ]
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You cannot, for example, create an array of a concrete parametrized type with the new operator. The issue relates to the runtime system being unable to guarantee type safety. Arrays are covariant and reified. Generics are invariant and non-reified.
Conversion of HashMap to ArrayList A HashMap contains key-value pairs, there are three ways to convert a HashMap to an ArrayList: Converting the HashMap keys into an ArrayList. Converting the HashMap values into an ArrayList. Converting the HashMap key-value pairs into an ArrayList.
Internally, the HashMap uses an Array, and it maps the labels to array indexes using a hash function. There are at least two ways to implement hashmap: Array: Using a hash function to map a key to the array index value.
What gives? It works. Just ignore it:
@SuppressWarnings("unchecked") No, you cannot parameterize it. I'd however rather use a List<Map<K, V>> instead.
List<Map<String, String>> listOfMaps = new ArrayList<Map<String, String>>(); To learn more about collections and maps, have a look at this tutorial.
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