for my program I need to create an array of ArrayLists.
Is this even possible?
This is the code I am trying to use:
public static ArrayList<Chemical> [] [] chemicals;
chemicals = new ArrayList<Chemical>[cols][rows];
It gives a generic array creation error.
Thank you.
This seems to work in Java 8
ArrayList<Chemical>[][] chemicals = new ArrayList[cols][rows];
Do this
public static ArrayList<Chemical> [] [] chemicals;
chemicals = new ArrayList[cols][rows];
and put @SuppressWarnings("unchecked") on the class
You can do it in following ways :
1.
List<List<Chemical>> listOfLists = new ArrayList<List<Chemical>>();
or other way :
2.
It may be more appropriate to use a Map<Chemical, List<Chemical>>. Having the value of the Map as a List<Chemical> will allow you to expand the list as opposed to an array which has a fixed size.
public static void main(String[] args) throws CloneNotSupportedException {
Map<Chemical, List<Chemical>> myMap = create(1, 3);
}
public static Map<Chemical, List<Chemical>> create(double row, double column) {
Map<Chemical, List<Chemical>> chemicalMap = new HashMap<Chemical, List<Chemical>>();
for (double x = 0; x < row; x++) {
for (double y = 0; y < column; y++) {
chemicalMap.put(x, new ArrayList<Chemical>());
}
}
return chemicalMap;
}
intrather thanIntegerafter marking it, but the similarity still exists even though I prefer yours.List Within listto overcome the problem of to defining row and column at coding time like List<List<Chemical>> listOfLists = new ArrayList<List<Chemical>>();