Create an array of HashMaps while specifying HashMap

Question

I am trying to create an array of HashMaps within a class and then retrieve a hashmap from the array for calculation purposes. Here is my code:

HashMap<String, Integer>[] boardPopulation= (HashMap<String, Integer>[]) new HashMap[populationSize];
    for(int i=0; i < populationSize; i++){
        generateQueens();
        boardPopulation[i] = queenMap;
    }
    for(int i=0; i < populationSize; i++){
        queenMap = boardPopulation[i];
        printBoard();
    }

When I compile I get two issues:

1. Board.java uses unchecked or unsafe operations, recompile with -Xlint:unchecked.
2. When I compile with "Xlint:unchecked" I get

Warning: [unchecked] unchecked cast HashMap[] boardPop.......(same as line 1 of above code)

required: HashMap[] found: HashMap[]

Please help me ! :D

Ideally I would like to not have to use Xlint unchecked, but ultimately I really just need to be able to retrive a HashMap from the list and assign it to queenMap so I can do calculations within the class.

Thankyou

Answer 1

Sorry for answering a slightly different question but if an array isn't essential, have you tried using a generic list:

List<Map<String, Integer>> boardPopulations = new ArrayList<>();
boardPopulations.add(new HashMap<>());